William R Watson
email: wwatson@iupui.edu

Sunnie Lee
email: suklee@indiana.edu

Sunnie Lee Watson

ARE LEARNING MANAGEMENT SYSTEMS 1 An Argument for Clarity: What are Learning Management Systems, What are They Not, and What Should They Become?

Keywords: Course Management Systems, E-learning, Integrated Learning System, Learning Content Management System, Learning Management System, Learning Object, Online Education, Learning Object, Virtual Learning Environment

    An argument for clarity: what are learning management systems, what are they not, and what should they become?

The application of computers to education has a history dating back to the 1950s, well before the pervasive spread of personal computers [START_REF] Reiser | Instructional Technology: A History[END_REF]. With a mature history and varying approaches to utilizing computers for education, a veritable alphabet soup of terms and acronyms related to computers in education have found their way into the literature, most of them non-standardized. Learning Management System (LMS) is one approach to the application of computers to education which holds great potential and important concepts yet is often misunderstood and the term misused. This article will clarify the use of the term LMS by presenting a history and definition of LMS, differentiating and contextualizing it from similar terms which it is often confused with, and discussing the role it can play in education. It will then describe its current application and available features, and conclude by identifying current trends and recommending future research.

History and Definition of LMS: What are LMSs?

The history of the application of computers to education is filled with generic terms such as computer-based instruction (CBI), computer-assisted instruction (CAI), and computer-assisted learning (CAL), generally describing drill-and-practice programs, more sophisticated tutorials, and more individualized instruction, respectively [START_REF] Parr | A Review of the Literature on Computer-Assisted Learning, particularly Integrated Learning Systems, and Outcomes with Respect to Literacy and Numeracy[END_REF]. LMS has its history in another term, integrated learning system (ILS) which offers additional functionality beyond instructional content such as management and tracking, more personalized instruction, and integration across the system [START_REF] Bailey | Wanted: A Road Map for Understanding Integrated Learning Systems[END_REF][START_REF] Becker | A Model for Improving the Performance of Integrated Learning Systems[END_REF][START_REF] Brush | Design and Delivery of Integrated Learning Systems: Their Impact on Students Achievement and Attitudes[END_REF][START_REF] Szabo | CMI Theory and Practice: Historical Roots of Learning Managment Systems[END_REF].

The term ILS was originally coined by Jostens Learning, and LMS was originally used to describe the management system part of the PLATO K-12 learning system, content-free and separate from the courseware (R. Foshay, personal communication, October 24, 2006). The term LMS is currently used to describe a number of different educational computer applications, and we would argue that it is often used incorrectly.

Later sections of this article will differentiate LMS from other terms which it is often confused with, but prior to describing what LMS is not; we will focus on describing what an LMS is.

The key to understanding the difference between LMS and other computer education terms is to understand the systemic nature of LMS. LMS is the framework that handles all aspects of the learning process. An LMS is the infrastructure that delivers and manages instructional content, identifies and assesses individual and organizational learning or training goals, tracks the progress towards meeting those goals, and collects and presents data for supervising the learning process of organization as a whole [START_REF] Szabo | CMI Theory and Practice: Historical Roots of Learning Managment Systems[END_REF]). An LMS delivers content but also handles registering for courses, course administration, skills gap analysis, tracking, and reporting [START_REF] Gilhooly | Making e-learning effective[END_REF]. [START_REF] Bailey | Wanted: A Road Map for Understanding Integrated Learning Systems[END_REF] integration with the Human Resources system; administration tools which enable the management of user registrations, profiles, roles, curricula, certification paths, tutor assignments, content, internal budgets, user payments and chargebacks, and scheduling for learners, instructors and classrooms; providing access to content, involving the medium (classroom, online), method (instructor-led, self-paced), and learners (employees, customers); developing content, including authoring, maintaining, and storing; integrating content with third-party courseware; assessing learners' competency gaps and managing skills acquisition and status;

providing and supporting authoring of assessments;

adhering to standards such as SCORM and AICC which allow for importing content and courseware that complies with standards regardless of what authoring system it was created in; supporting configuration of the LMS to function with existing systems and internal processes; and providing security such as passwords and encryption.

While this list of features can be helpful in understanding what an LMS is, as a systemic application, it incorporates a great many features by providing the structure of the entire learning process within an organization. Therefore, further clarity can be achieved by contrasting it with related technologies which it is often confused with.

Relating LMS to CMS, LCMS, and RLO: What are LMSs not?

As the application of computers to education is awash with acronym-driven, nonstandardized terms, it is not surprising that there is often confusion as to which term is appropriate to use. A major goal of this article is to recommend a consistent use of the term LMS in the literature. In order to do this, it is important to identify some of the ways in which we believe LMS is being inappropriately used to describe separate but related technologies.

Course Management Systems

The inappropriate use of LMS in the literature is perhaps most commonly associated with computer applications which we would identify as Course Management Systems (CMS). These systems are used primarily for online or blended learning, supporting the placement of course materials online, associating students with courses, tracking student performance, storing student submissions, and mediating communication between the students as well as their instructor. Some of this same functionality can be seen within LMSs as well, so it is understandable why confusion might exist. However, the systemic nature of an LMS does not limit its functionality to that of a CMS.

A CMS "provides an instructor with a set of tools and a framework that allows the relatively easy creation of online course content and the subsequent teaching and management of that course including various interactions with students taking the course" (EDUCAUSE Evolving Technologies Committee, 2003, p. 1). Examples of a CMS include Blackboard, Angel, Sakai, Oncourse, and Moogle. However, Blackboard is a good example of the confusion that exists regarding these terms as it is commonly referred to as an LMS in the literature.

A Google Scholar search of the phrase "blackboard lms" returned 36 articles identifying Blackboard as an LMS, while the Blackboard company itself refers to its product as a CMS: "Blackboard's online learning application, the Blackboard Learning System, is the most widely-adopted course management system [emphasis added] among U.S. postsecondary institutions" ("Blackboard Company", 2006). While Blackboard's Learning System does not compose their entire Academic Suite, the additional products support better management of learning objects, student portfolios, and the creation of online portals , which collectively Blackboard calls a Networked Learning Environment ("Blackboard Academic Suite brochure", 2006), does not meet the full functionality necessary to be identified as an LMS. The scope of functionalities does not encompass the entire organization, and the course-focused nature of the applications is not systemic. Therefore, while a CMS could be seen as a part of an LMS, it is certainly not equivalent to an LMS. The technologies were developed for very different reasons even if they share certain functionalities [START_REF] Carliner | Course Management Systems versus Learning Management Systems[END_REF].

Learning Content Management Systems

While also being frequently confused with each other, Learning Content Management Systems (LCMS) and LMSs can be more simply contrasted as they are very well suited to integrate with each other. LCMS is often used interchangeably with LMS or touted as a newer version of LMS. In reality, the two applications focus on different functions and complement each other well. The key difference between the two technologies is as simple as the one word separating them: content. [START_REF] Oakes | E-learning: LCMS, LMS-They're not just acronyms but powerful systems for learning[END_REF] reports that the IDC defines an LCMS as a system used to "create, store, assemble and deliver personalized e-learning content in the form of learning objects" (p. 73). The focus with LCMS is content as "it tackles the challenges of creating, reusing, managing, and delivering content" (Oakes, 2002, p. 74). An LMS, however, is "learner and organization focused: It's concerned with the logistics of managing learners, learning activities and the competency mapping of an organization" (Oakes, 2002, p. 74).

LCMS and LMS certainly have a different focus but integrate very well; the LCMS allows for the creation and delivery of learning objects (LO) while LMS manages the learning process as a whole, incorporating the LCMS within it [START_REF] Greenberg | LMS and LCMS: What's the Difference?[END_REF]. Or as [START_REF] Connolly | A standard for success[END_REF] puts it "LMS provides the rules and the LCMS provides the content" (p. 58).

Learning Objects and Integrating These Related Technologies

Having described the complementary nature of LCMSs and LMS as well as the different focus of CMS and LMS, and understanding the systemic nature of LMS as providing the structure within which CMS and LCMS can function, we will now examine an important technology, learning objects, which is not typically confused with LMS but which is inherently important to the integration of these related technologies. A LO represents the smallest component of content within an LCMS or LMS. LOs offer powerful potential due to their promise of reusability across multiple contexts, generativity (integrating LOs to generate new instruction), adaptability to meet the needs of individual learners, and scalability to meet the needs of both larger and smaller audiences without significant changes in cost [START_REF] Gibbons | The nature and origin of instructional objects[END_REF][START_REF] Hodgins | The future of learning objects[END_REF][START_REF] Wiley | Connecting learning objects to instructional design theory: A definition, a metaphor, and a taxonomy[END_REF].

Essentially, a learning object can be defined as any digital media that can be reused to support learning [START_REF] Watson | Learning Management Systems: An overview and roadmap of the systemic application of computers to education[END_REF]. It is reusable nature of the LO which holds the most promise and challenges for success. In order to maximize a LOs reusability, it must adhere to standards such as SCORM or LOM which utilize metadata to describe the object as well as the context for its use. Unfortunately, there are multiple standards for describing LOs in use as well as multiple standards "for evaluating interoperability between LMSs and content" [START_REF] Connolly | A standard for success[END_REF] p. 57 such as LOs.

The lack of agreement and adherence to standards with both the creation of LOs and their inclusion in LMSs results in a negative impact on reusability, flexibility and functionality. Ideally, LOs, CMS, LCMS would be integrated together within the LMS which would act as the infrastructure to seamlessly bring together these complementary technologies. LOs would act as the smallest form of content, created and delivered within an LCMS according to each individual learner's need based on current assessments and performance toward customized learning goals, handled by the LMS. The CMS would function as a course environment, organizing instructional content into discrete courses and supporting communication between learners as well as their instructors.

Role of LMS in Education: What should LMSs become?

The importance of understanding LMS as well as its related technologies lies in the role it will play in future approaches to instruction as the needs of today's learners are not being met by current approaches. Society has shifted from the Industrial Age into what many are calling the Information Age [START_REF] Reigeluth | The Imperative for Systemic Change[END_REF]Senge, Cambron-McCade, Lucas, Smith, Dutton, & Kleiner, 2000;[START_REF] Toffler | The Third Wave[END_REF]. Today's education system remains mired in the Industrial Age, putting the onus for learning on teachers, encouraging students to remain passive, and treating all students as if they are the same and forcing them to do the same things in the same amount of time [START_REF] Reigeluth | The Imperative for Systemic Change[END_REF].

This forces achievement to vary among the students, leaving the low-achieving students behind and holding the higher-achieving students back [START_REF] Reigeluth | Educational standards: To standardize or to customize learning?[END_REF]. The alternative to holding time constant and forcing learning to occur at a single rate is to hold achievement at a constant mastery level. This requires education to shift to an entirely new paradigm, from one with a focus on standardization and sorting with a high rate of failure to one that supports customization to meet all learners' needs.

In an Information Age appropriate paradigm of education, students will be allowed as much time as they need to achieve mastery as well as allowed to move on immediately upon demonstrating that mastery, requiring a customized pace and sequencing of instruction [START_REF] Schlechty | Schools for the 21st century: Leadership imperatives for educational reform[END_REF]. Furthermore, instruction will move to a more learner-centered approach as teachers cease acting primarily as knowledge sources and instead become facilitators of the knowledge acquisition process by acting as guides, coaches, and motivators as students become more active in their learning process [START_REF] Mccombs | The learner-centered classroom and school[END_REF].

In order for the learner process to be customized for each individual learner, technology will need to play a key role. [START_REF] Schlechty | Schools for the 21st century: Leadership imperatives for educational reform[END_REF] argues that technology will be needed to track each student's progress towards mastery, assess their learning, help teachers understand what sort of guidance is needed, provide and appropriately sequence instruction, store evidence of attainments, and systemically integrate each of these functions. It is clear that this description is closely aligned to the functions of a LMS.

In an Information Age model of education, a LMS will assess learners' current knowledge and skill level, work with teachers and learners to identify appropriate learning goals, identify and sequence instruction appropriate for the individual learner, assess learner performance products, store evidence of attainments, support collaboration, and generate reports to provide information to maximize the effectiveness of the entire learning organization. While LMSs can currently perform some of this functionality, limitations exist which are hindering the full realization of LMSs' potential.

We have previously discussed the challenges presented by lack of agreement and adherence regarding standards which causes a trickle down impact negatively impacting the reusability of learning objects and the effectiveness and efficiency of LMSs. LOs are difficult enough to create but the challenges of then applying standards which will result in easy implementation within a LCMS or LMS are an additional headache for instructional designers. Without effective use of standards, even a LO well suited to broad reuse is unlikely to reused simply due to the lack of awareness regarding its availability. Some work is currently being done on Automatic Meta-data Generation (AMG) in order to ease the load on designers to have to tie their instruction to standards themselves ("Introduction: why we need AMG, first version, and redesign", 2006).

Furthermore, the challenges of creating effective LOs needs to be addressed with better authoring tools allowing for the creation of effective instruction suitable for specific types of learners. Many of the current K-12 LMS platforms utilize older instruction which has been minimally updated if at all. The reason is the immense cost in developing the instruction, estimated as high as $100 million to build a comparative system today (R. Foshay, personal communication, October 24, 2006). By incorporating authoring tools to allow for easier creation of learning objects by practitioners, some of this challenge can be overcome.

The increasing availability of open-source technologies is another potential advantage, dispersing the resource load for creating, updating, and maintaining these technologies across a global community of developers rather than one or two private companies. Ultimately, LMSs need to: provide more constructivist-based instruction, focusing on flexible, learnerdefined goals [START_REF] Reigeluth | Envisioning a New System of Education[END_REF], support collaborative learning inside and outside of the school in order to extend the learning environment to the home and further involve parents [START_REF] Taylor | Education technology helps unite school communities, improve academic achievement T[END_REF] better address personalized assessment, progress tracking, reporting, and responsiveness to learner needs [START_REF] Reigeluth | Envisioning a New System of Education[END_REF], truly become systemic, integrating systems seamlessly to allow for improved collaboration across systems and among stakeholders [START_REF] Sherry | Integrated Learning Systems: What May We Expect in the Future[END_REF], improve support for professional diagnosis and development for stakeholders, including teachers, and improve cost effectiveness and better leverage existing resources currently available in schools and LMSs [START_REF] Szabo | CMI Theory and Practice: Historical Roots of Learning Managment Systems[END_REF].

While serious challenges exist which are currently impeding LMSs from realizing their full potential, perhaps the greatest possibility for improving these technologies lies in the hands of learners, teachers, and other stakeholders in the current educational system. That is, once they demand a shift to an Information Age paradigm of instruction, the full and centralized implementation of LMSs will be necessary, and the attention to maximizing their potential will naturally be realized.

Overview of major LMS: What do current LMSs offer?

This final section will present an overview of the status of several major LMSs available today. LMSs are more typically utilized in corporate settings with many available systems on the market, including NetDimensions EKP, Saba, and SumTotal Systems [START_REF] Carliner | Course Management Systems versus Learning Management Systems[END_REF], as well as Lotus, Oracle iLearning, and Cornerstone OnDemand, among others ("A field guide to learning management systems", 2005). A currently being utilized ("2006Survey of Learning Management Systems", 2006).

In the K-12 market, two major systems have been absorbing the smaller products over the last several years. The following table reflects a summary of the previous research we have conducted in which we generated a conceptual framework of major features in order to evaluate and compare the major K-12 LMSs [START_REF] Watson | Learning Management Systems: An overview and roadmap of the systemic application of computers to education[END_REF]. We reviewed corporate literature to identify which features each LMS offered, and with the exception of PLATO whose representatives declined comment, had each company review and approve our conclusions. It should be stated that while the table represents our conclusions, the LMSs are composed of multiple products, and it is unclear how well these products function together, so it is possible that not all features listed will function together as a complete package. Furthermore, some of the features are more of a matter of degree rather than a simple yes or no.

We have updated the table as Pearson Digital Learning recently purchased Conect, and we made a small change in wording regarding the direct instruction feature to better reflect our original intentions of the meaning of the word in the LMS context.

Apart from the list of features, the table also lists shaded features which represent features important for the Information Age paradigm of instruction.

  presents the following general characteristics for an LMS in education: instructional objectives are tied to individual lessons; lessons are incorporated into the standardized curriculum; courseware extends several grade levels in a consistent manner; a management system collects the results of student performance; and lessons are provided based on the individual student's learning progress. The American Society for Training & Development ("A field guide to learning management systems", 2005), recommends the following functional requirements for a corporate LMS:

Table 1 :

 1 Comparison of major features of K-12 LMS products Conclusion LMSs are a powerful technology that have yet to reach their full potential and are very important for the Information Age paradigm of education. Because of their importance, greater care and understanding needs to be used when applying the term in research literature. By coming to an understanding of what LMSs are and how complementary technologies can be integrated with an LMS, researchers and practitioners will better be able to communicate regarding the state and future of Running Head: WHAT ARE LEARNING MANAGEMENT SYSTEMS 15 computers in education. However, understanding and consistent use of terms alone is not sufficient for the potential of computer technologies in education to be realized. There is a real dearth of solid research on LMSs. Studies about the implementation and effectiveness of the LMS products examined in this article are needed. These studies should examine more closely what features these products offer as well as identify what additional features are needed. Student, teacher, parent, and other stakeholder perceptions of these products as well as the individual features should be described. Furthermore, more research is needed in the area of learning object authoring and adherence to standards. With the constant adoption and discarding of terms in the fast-paced world of computers, communication can be hindered, concepts blurred, and research stunted. It is important to keep an eye on the needs of today's learners, how technology can be maximized to best meet those needs, and to conduct research to help guide decisions and future applications of technology.

	Features (grayed features support information-age needs)	PLATO	Pearson Digital Learning	Achievement Technologies


Fleur P Velders

Gwen Dieleman

Jens Henrichs

Vincent W V Jaddoe

Albert Hofman

Frank C Verhulst

James J Hudziak

Henning Tiemeier
email: h.tiemeier@erasmusmc.nl

Prenatal and postnatal psychological symptoms of parents and family functioning: the impact on child emotional and behavioural problems

Keywords: family functioning, psychopathology, depression, hostility, child emotional and behavioural problems

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

A broad range of psychological problems of parents places children at risk for the development of emotional and behavioural problems. A key example is the effect of maternal depression on child development.

Not only is depression in children of depressed mothers more frequent and more severe than in children of nondepressed mothers, but these children also display more anxiety disorders, aggression, attention deficits, insecure attachment, poor self-esteem and poor peer relations [START_REF] Gelfand | The effects of maternal depression on children[END_REF][START_REF] Goodman | Depression in mothers[END_REF]. The relation between psychopathology of parents and child development is not limited to the mother-child relationship [START_REF] Phares | The role of fathers in child and adollescent psychopathology: Make room for daddy[END_REF][START_REF] Ramchandani | Paternal psychiatric disorders and children's psychosocial development[END_REF]. For instance, postnatal paternal depression was associated with a higher likelihood of a psychiatric diagnosis in children at the age of 7 [START_REF] Ramchandani | Depression in men in the postnatal period and later child psychopathology: A population cohort study[END_REF]. Next to the evidence for a postnatal effect of parental psychopathology on child development, there are also several reports suggesting a direct relation between maternal stress during pregnancy, such as depression and anxiety, and child development [START_REF] Van Den Bergh | Antenatal maternal anxiety and stress and the neurobehavioural development of the fetus and child: Links and possible mechanisms. A review[END_REF]. Interestingly, father s' prenatal depression has also been associated with child development such as excessive infant crying [START_REF] Van Den Berg | Paternal depressive symptoms during pregnancy are related to excessive infant crying[END_REF], child anxiety [START_REF] Colletti | Parent depression and child anxiety: An overview of the literature with clinical implications[END_REF], and conduct problems [START_REF] Ramchandani | The effects of pre-and postnatal depression in fathers: A natural experiment comparing the effects of exposure to depression on offspring[END_REF]. Genetic effects, programming effects in utero and differentiation effects after birth may account for these prenatal and postnatal associations [START_REF] Lupien | Effects of stress throughout the lifespan on the brain, behaviour and cognition[END_REF]. During pregnancy, the comparison of the effect of maternal risk factors on the likelihood of child internalizing problems with the effect of paternal risk factors has been used to investigate the causality of the underlying association [START_REF] Brion | Intrauterine effects of maternal prepregnancy overweight on child cognition and behavior in 2 cohorts[END_REF]. If only a maternal prenatal relation is found, this may be the result of specific intra-uterine programming effects. A prenatal effect of paternal risk factors more likely reflects long lasting effects such as a genetic risk for psychopathology or residual confounding (i.e. unmeasured variables account for the association).

Like depression, parental hostility is also a significant threat to child development [START_REF] Gordis | Parents' hostility in dyadic marital and triadic family settings and children's behavior problems[END_REF][START_REF] Richmond | Longitudinal associations between parents' hostility and siblings' externalizing behavior in the context of marital discord[END_REF]. Hostile behaviour of mothers and fathers is related to less optimal interactions with their children [START_REF] Low | Family functioning and children's adjustment: Associations among parents' depressed mood, marital hostility, parent-child hostility, and children's adjustment[END_REF]. Parent-child hostility gives rise to fear, anger and distress, and increases the likelihood of aggressive behaviour and anxiety of the child [START_REF] Emery | Interparental conflict and the children of discord and divorce[END_REF][START_REF] Low | Family functioning and children's adjustment: Associations among parents' depressed mood, marital hostility, parent-child hostility, and children's adjustment[END_REF]. The actual effect of parental hostility seems to depend mainly on emotional and cognitive processes within the child, and on family processes such as the level of involvement of the child in parental disputes [START_REF] Fosco | Emotional, cognitive, and family systems mediators of children's adjustment to interparental conflict[END_REF].

By way of daily interaction within families, parental psychopathology usually also affects contextual factors. In families with a depressed parent, the interaction between spouses is often characterized by increased hostility and tension [START_REF] Kahn | Depression and marital disagreement: The social construction of despair[END_REF]. These families report poor family functioning more frequently than families with no depressed parents [START_REF] Hughes | Internalizing symptoms and disorders in families of adolescents: A review of family systems literature[END_REF]. Therefore, children in these families are not only at an increased risk of emotional and behavioural problems, because they have a parent with psychological problems, but also due to an increased likelihood of exposure to marital conflict and poor family functioning.

Previous research mostly focused on the interrelation of parental depression, hostility, marital conflict and family functioning on child development, and mediators of these associations [START_REF] Katz | Spillover effects of marital conflict: In search of parenting and coparenting mechanisms[END_REF][START_REF] Goodman | Risk for psychopathology in the children of depressed mothers: A developmental model for understanding mechanisms of transmission[END_REF][START_REF] Rehman | The marital context of depression: Research, limitations, and new directions[END_REF][START_REF] Fosco | Emotional, cognitive, and family systems mediators of children's adjustment to interparental conflict[END_REF]. In a recent review in this field, it was suggested that parental psychopathology and family functioning have reciprocal effects without a causal primacy of one of the two [START_REF] Rehman | The marital context of depression: Research, limitations, and new directions[END_REF]. The debate remains to what extent these apparent risk factors independently contribute to child problem behaviour when analysed simultaneously. Insight in the independent contributions of parental depression, parental hostility and family functioning to the risk of child problem behaviour is important for the development of effective prevention and intervention strategies.

In the present study, we aimed to test the following hypotheses, 1) prenatal psychological symptoms of parents are a risk factor for child emotional and behavioural problems independent of postnatal parental symptoms, 2) parental depressive symptoms and parental symptoms of hostility each contribute to the risk of emotional and behavioural problems in children. Given the dyadic nature of family functioning, we also expected to find an additional effect of family functioning on the risk of child problems, and 3) any prenatal effect of maternal psychological symptoms exceeds the effect of paternal psychological symptoms during pregnancy, due to direct physiologic effects via the mother on the intrauterine environment of the fetus.

We tested these hypotheses in 2698 families participating in an ongoing population-based cohort. To explore the specificity of our findings, we also examined the effect of other parental psychological symptoms, such as psychoticism and anxiety, on child emotional and behavioural problems. Furthermore, we examined the effect of parental depressive symptoms, parental hostility, and family functioning on subtypes of emotional and behavioural problems; emotionally reactive behaviour, anxious/depressed behaviour, somatic complaints, withdrawn behaviour, attention problems and aggressive behaviour.

Methods

Design

This study was embedded in the Generation R Study, a population-based cohort from foetal life onwards in Rotterdam, the Netherlands. The Generation R Study has previously been described in detail [START_REF] Jaddoe | The generation r study: Design and cohort update 2010[END_REF]

Population of analysis

In the Generation R cohort, complete information on depressive symptoms, symptoms of hostility during pregnancy and family functioning was obtained from 3425 mothers and fathers. Families without father participation were not included in this study. Of the 3425 couples, 2698 filled out the questionnaire about child behaviour. Hence in total, 2698 couples and children (79% of 3425) were included in the analyses.

Prenatal and postnatal psychological symptoms of the parents

Psychological symptoms of the parents were assessed at 20 weeks of pregnancy and when the child was three years old with the Brief Symptom Inventory (BSI), a validated self-report questionnaire with 53 items to be answered on a five-point scale, ranging from "0=not at all" to "4=extremely" [START_REF] Beurs D | Brief symptom inventory, handleiding[END_REF][START_REF] Derogatis | Brief symptom inventory (bsi): Administration, scoring and procedures[END_REF]. These 53 items are classified in eight subscales; Depression, Hostility, Anxiety, Phobic Anxiety, Paranoid Ideation, Psychoticism, Interpersonal Sensitivity and Obsessive-Compulsive. This study focused mainly on depression and hostility. The Depression scale consists of 6 items e.g. "I am feeling suicidal" and "I have no interest in anything". The Hostility scale consists of 5 items e.g. "I have an urge to hit, injure or cause pain to others" and "I often get involved in arguments". Higher scores on these scales represent an increased occurrence of depressive symptoms or symptoms of hostility.

Prenatal family functioning

Family functioning was assessed by the subscale General Functioning of the Family Assessment Device [25] at 20 weeks pregnancy. General Functioning is a validated overall self-report measure of health and pathology of a family and consists of 12 items. Half of the items describe healthy functioning, e.g. "In times of crisis, we can turn to each other for support". The other half describes unhealthy items, e.g. "There are a lot of unpleasant and painful feelings in our family." Parents were asked to rate how well each item described their family by selecting from four different responses: strongly agree, agree, disagree or strongly disagree. The scores per item were summed and divided by 12 yielding a total score from 1 to 4. A higher total score translates into less well functioning families or poor family functioning.

Child behaviour

The Child Behavior Checklist/1½-5 (CBCL/1½-5) was used to obtain standardized parent reports of children's problem behaviour at the age of 3 years. This behavioural questionnaire contains 99 items, which are scored on a three-point scale; 0 = not true, 1 = somewhat true or sometimes true and 2 = very or often true, based on the two preceding months. The Total Problems score is obtained by summing the scores of all 99 items. The Internalizing scale score is a sum score of the items (N=36) in four syndrome scales: Emotionally Reactive, Anxious/Depressed, Somatic Complaints, and Withdrawn. The Externalizing scale score is a sum score of the items (N=24) in the Attention Problems and Aggressive Behavior syndrome scales. The psychometric properties of the CBCL are well established [START_REF] Achenbach | Manual for the aseba preschool form & profiles[END_REF]. In this study, we used the broadband scale Internalizing scale, the Externalizing scale and the syndrome scales (emotionally reactive, anxious/depressed, somatic complaints, withdrawn, attention problems, and aggression). The data could not be normalized and were analyzed as dichotomized variables. To obtain a score on emotional and behavioural problems based on the report of both parents, the scores on Internalizing and Externalizing of mother and father were standardized (Z-scores) and averaged. If only the score of one parent was available, this score was used (12%). Dutch norm scores have not been published. As in previous analyses, we defined a non-optimal score as the highest 20 percent of Internalizing and Externalizing item scores [START_REF] Cents | Grandparental anxiety and depression predict young children's internalizing and externalizing problems the generation r study[END_REF]. Likewise we calculated non-optimal scores of the syndrome scales.

Other measurements

Information on infant birth weight and gender were obtained from midwife and hospital registries. Gestational age was established by foetal ultrasound examinations within the Generation R Study. Information on parental age at child birth, parental educational level, maternal smoking and maternal alcohol use during pregnancy, birth order, age of the infant, and ethnicity of the infant was obtained by questionnaire. The highest completed education (primary school, secondary school and higher education) determined the educational level of the parents. Ethnicity of the infant was classified into two categories based on the parental country of birth. If both parents were non-Dutch, mother's ethnicity determined the ethnicity of the child. The group of children classified as Western includes Dutch, American Western (non-Hispanic Whites), Asian Western (Japan), European and Australian children. The Non-Western group is comprised of children with a Turkish, Moroccan, Surinamese, Cape Verdean, Dutch Antillean, African, American non-Western (Afro-Americans, Hispanics) and Asian non-Western (Asia except Japan) ethnicity [START_REF]Allochtonen in Nederland 2004[END_REF]. Maternal smoking and maternal alcohol use were assessed at three time-points during pregnancy and categorized into "yes, during pregnancy" and "never during pregnancy". The inclusion of these potential confounders was determined a priori and based on existing knowledge about the association between parental psychopathology and child behaviour [START_REF] Van Den Bergh | Antenatal maternal anxiety and stress and the neurobehavioural development of the fetus and child: Links and possible mechanisms. A review[END_REF].

Statistical analysis

In a non-response analysis, differences in baseline characteristics of responders (n=2698) and nonresponders (n=727) on the assessment of child behaviour were compared with the chi-square statistic for categorical variables, the independent t-test for normally distributed continuous variables and the Mann Whitney U test for non-normally distributed continuous variables. Likewise, we compared baseline characteristics between children with low scores on emotional and behavioural problems and children with high scores on emotional and behavioural problems. The correlation between the determinants was analyzed using the Spearman's correlation coefficient for non-parametric variables ( sp ). The continuous measures of parental depressive symptoms, family functioning and symptoms of hostility were expressed per standard deviation to facilitate comparisons of effect sizes.

First, we examined the direct effect of prenatal depressive symptoms, prenatal hostility symptoms, prenatal family functioning, postnatal depressive symptoms and postnatal hostility symptoms of the parents on child internalizing problems and child externalizing problems. These multivariate linear regression analyses were adjusted for covariates, but not for the other determinants. To test the specificity of these associations for depressive symptoms and hostility, we additionally examined the association of other prenatal maternal BSI subscales (Phobic Anxiety, Psychoticism, Paranoid Ideation, Obsessive-Compulsive, Interpersonal Sensitivity, Somatization and Anxiety) with child internalizing and externalizing problems.

Second, we examined the independent contribution of parental psychological problems and family functioning to the development of child internalizing and externalizing problems using multivariate linear regression analyses in five successive models. The first three models included the prenatal determinants, whereas the postnatal determinants were added in model 4 and model 5. To test for significant difference between the odds ratios, we produced 84% confidence intervals (84%CI) around the odds ratios and examined the overlap.

As reported by Julious, the level of statistical significance between the two groups would be 5% or lower if the 84% confidence intervals around the odds ratios do not overlap [START_REF] Julious | Using confidence intervals around individual means to assess statistical significance between two means[END_REF]. Third, we examined the association of parental psychological symptoms and family functioning with subtypes of internalizing and externalizing problems (model 5).

All analyses were controlled for child gender, birth weight, birth order, child ethnicity, child age, maternal smoking and drinking behaviour during pregnancy, parental age, as well as for parental education.

Missing data were imputed using multiple imputation procedures. Test statistics and regression coefficients were averaged across five imputed data sets [30]. The level of significance for all analyses was set at = .05. All statistical analyses were carried out using PASW Statistics, version 17.0 for Windows [30].

Non-response analysis

Mothers who did not complete the CBCL/1½-5 were on average younger at child birth (29.2yrs. vs. 31.6yrs., t=12.27, p<0.001), were less likely high educated (20.3% vs. 37.5%, 2 =76.17(1df), p<0.001), and more likely to smoke during pregnancy (26.2% vs. 18.5%, 2 =21.06(1df), p<0.001 than responding mothers. Likewise, fathers who did not complete the CBCL/1½-5 were on average younger at child birth (32.2yrs. vs. 33.9yrs., t=6.598, p<0.001), and were less high educated (26.5% vs. 40.1%, 2 =45.67(1df), p<0.001) than responding fathers. Children of non-responding mothers had on average a lower birth weight (3363gram vs. 3480gram, t=5.05, p<0.001) and the origin of these children was less likely Dutch or Western (63.6% vs. 84.8%, 2 =163.161df), p<0.001) compared with children of mothers who did complete the CBCL/1½-5 .

Results

Table 1 presents the subject characteristics in the group of children with low internalizing problems compared with the subject characteristics in the group of children with high internalizing problems. Mothers of children with high internalizing problems were on average younger at child birth (mean 30.8 yrs. vs. 31.8 yrs., t=5.39, p<0.001) and were less likely highly educated (33.8% vs. 39.2%, 2 =5.06(1df), p=0.021) than mothers of children with low internalizing problems. Paternal characteristics showed a similar distribution over the groups compared with maternal characteristics. The children with high internalizing problems were more likely firstborns (72.8% vs. 60.5%, 2 =27.88(1df), p<0.001), had on average a lower birth weight (3422gram vs. 3495gram, t: 2.27, p=0.006) and were less often of Western origin (78.3% vs. 86.9%, 2 =19.71(1df), p<0.001) compared with children with low internalizing problem scores. The comparison of children with low externalizing problems and high externalizing problems showed a similar distribution of characteristics, except for maternal smoking during pregnancy (% never during pregnancy 82.9 vs. 76.0, 2 =13.96(1df , p<0.001) and gender (% boys 47.1 vs. 60.3, 2 =29.74(1df , p<0.001) (data not shown).

Prenatal depressive symptoms, prenatal hostility, prenatal family functioning, postnatal depressive symptoms and postnatal hostility of the parents were significantly correlated (p-value <0.001), and the highest correlation was found between depressive symptoms and symptoms of hostility (e.g. sp prenatal maternal depressive symptoms -prenatal maternal hostility 0.50, p-value <0.001) (Appendix table 1). Co-linearity among BSI sub-scales was indicated by correlations of .31 to .64. For instance, we found a correlation of 0.52 for BSI depression and BSI anxiety, for BSI depression with BSI phobic anxiety a correlation of 0.37, for BSI hostility with BSI anxiety a correlation of 0.48 and a correlation for hostility with phobic anxiety of 0.31.

As presented in table 2, parental prenatal depressive symptoms, parental prenatal symptoms of hostility, parental prenatal family functioning, parental postnatal depressive symptom and parental postnatal symptoms of hostility were all significantly associated with an increased likelihood of child internalizing problems (OR range In table 3, we present the association of parental psychological symptoms and family functioning with child internalizing problems in 5 successive models. The prenatal analyses showed that prenatal depressive symptoms of mothers and fathers each predicted internalizing problems (model 1). However, these associations were no longer significant when prenatal parental hostility was added to the regression analysis (model 2). In model 3, a higher score on prenatal family functioning experienced by the mother was associated with an increased risk of child internalizing problems (OR 1.25, 95%CI 1.12; 1.39, p-value <0.001). Prenatal family functioning experienced by the father was not significantly associated with child internalizing problems. In model 4 and 5 postnatal determinants were added to the analyses. As shown in these models, we found that the initially significant associations of postnatal depressive symptoms of mother and father with an increased risk of internalizing problems were no longer significant after adding postnatal parental symptoms of hostility. The final model (model 5) showed that poor family functioning experienced by the mother during pregnancy (OR1.23, 95%CI 1.10; 1.37, p-value <0.001), postnatal symptoms of hostility of mother (OR1.35, 95%CI 1.20; 1.52, pvalue <0.001), and postnatal symptoms of hostility of father (OR1.30, 95%CI 1.17;1.46, p-value <0.001) were all independently associated with an increased risk of child internalizing problems. The same pattern was found for the associations between the determinants and child externalizing problems (table 4); postnatal symptoms of hostility of the mother (OR1.34, 95%CI 1.20; 1.50, p-value <0.001) and of the father (OR1.33, 95%CI 1.19; 1.48, p-value <0.001) independently contributed to the likelihood of child externalizing problems. Also, the effects of the determinants on the risk of child internalizing problems and child externalizing problems were not significantly different, since the 84% confidence intervals of the ORs overlap (data not shown).

The analyses of parental psychopathology symptoms and prenatal family functioning with subtypes of internalizing problems and externalizing problems showed that postnatal symptoms of hostility of mothers and fathers each significantly increased the likelihood of all six subtypes of child emotional and behavioural problems at the age of three years (OR range 1.15-1.37) (see appendix table 2 and appendix table 3). Next to these significant observations, prenatal depressive symptoms of the mother were primarily related to anxious/depressed behaviour and emotionally reactive behaviour. Prenatal symptoms of hostility of the mother predicted child aggressive behaviour, whereas prenatal symptoms of hostility of the father were significantly associated with emotionally reactive behaviour of the child. Furthermore, prenatal family functioning reported by the mother was associated with anxious/depressed behaviour, emotionally reactive behaviour and somatic complaints, whereas prenatal family functioning reported by the father was related to somatic complaints of children (see appendix table 2 and appendix table 3).

Discussion

This study examined the risk of prenatal and postnatal parental depressive symptoms, prenatal and postnatal parental hostility and prenatal family functioning for emotional and behavioural problems in young children. We first evaluate prenatal and postnatal effects of parental psychological symptoms. The associations of parental prenatal depressive symptoms and prenatal hostility of the parents with child internalizing and externalizing problems were not independent of the effect of postnatal parental hostility with the outcome. This may suggest that parent-child interaction is essential to determine the impact of parental psychopathology on children, or that it is easier to detect an immediate effect than a distant effect of a stressor on child development.

However, these findings make it also more likely that the effects of postnatal parental symptoms of hostility on child behaviour are causal, because some form of hostility in the parent was already present before birth of the child. Child emotional and behavioural problems can be a source of postnatal parental psychological problems [START_REF] Gordis | Parents' hostility in dyadic marital and triadic family settings and children's behavior problems[END_REF][START_REF] Richmond | Longitudinal associations between parents' hostility and siblings' externalizing behavior in the context of marital discord[END_REF], but this reasoning cannot account for parental hostility prior to birth of the offspring, thus reverse causality is less likely.

Our second hypothesis posited that parental depressive symptoms, parental hostility and family functioning would have independent effects on child development. Although initially significant, the effects of parental depressive symptoms on child internalizing problems and child externalizing problems were accounted for by postnatal parental hostility. Hence, when analysed simultaneously with parental depressive symptoms, the impact of parental hostility after birth on child development seemed larger. However, we cannot conclude that depressive symptoms of the parents do not affect these families. It has been reported that persons with a depression show more nonverbal expressions of hostility in their interactions than non depressed persons [START_REF] Troisi | Gender differences in depression: An ethological study of nonverbal behavior during interviews[END_REF]. In our study, this comorbidity was reflected by moderately strong correlations between depressive symptoms and symptoms of hostility. Also, in the subtype analyses, prenatal maternal depressive symptoms significantly predicted child anxious/depressed behaviour and emotionally reactive behaviour, independent of parental hostility.

We also report that poor family functioning during pregnancy experienced by the mother increases the risk of child internalizing problems, independently of the increased risk associated with parental postnatal hostility. The association between family functioning and child behavioural problems has been previously documented [START_REF] Emery | Interparental conflict and the children of discord and divorce[END_REF][START_REF] Grych | Marital conflict and children's adjustment: A cognitivecontextual framework[END_REF]. In this field of research, many studies however focused on the combined effect of family functioning and parental psychopathology on child development [START_REF] Fosco | Emotional, cognitive, and family systems mediators of children's adjustment to interparental conflict[END_REF][START_REF] Goodman | Risk for psychopathology in the children of depressed mothers: A developmental model for understanding mechanisms of transmission[END_REF][START_REF] Grych | Marital conflict and children's adjustment: A cognitivecontextual framework[END_REF][START_REF] Katz | Spillover effects of marital conflict: In search of parenting and coparenting mechanisms[END_REF][START_REF] Low | Family functioning and children's adjustment: Associations among parents' depressed mood, marital hostility, parent-child hostility, and children's adjustment[END_REF]. Our findings seem to underscore the importance of family life to child development, next to the effect of parental symptoms of psychopathology. Interestingly, this association may be specific for child internalizing problems, as we did not find an independent effect of prenatal family functioning on child externalizing problems.

To test the third hypothesis, we focused on the effects of maternal risk factors and the effects of paternal risk factors on child emotional and behavioural problems. Remarkably, the postnatal effect of father's hostility was similar to the effect estimate of mother's hostility on the likelihood of child internalizing and externalizing problems. These findings underscore the importance of father's behaviour on child development, and point to the fact that even subtle hostility by father affects their children. In contrast, father's experience of family functioning was not significantly associated with child internalizing problems. Fathers may have different views on family functioning compared to mothers. In our study, however, mothers and fathers report quite similar on family functioning in terms of total range of scores and mean scores. As both parents' reports of family functioning were included in one regression model (table 3), it may also be that the effect of father's experience of family functioning is captured in mother's experience of family functioning.

Two methodological considerations need to be discussed. First, we want to address the specificity of our findings. The associations of parental depressive symptoms and hostility with child internalizing and externalizing problems were not specific; other BSI subscales also predicted child problems. This indicates strongly that these scales partly represent general psychopathology. We also found similar effects of postnatal parental hostility on child internalizing and child externalizing problems. If anything, family functioning reported by the mother was associated with a somewhat higher risk of internalizing problems compared with externalizing problems. This absence of effect specificity is not surprising, given the high level of comorbidity among psychiatric disorders in children [START_REF] Angold | Comorbidity[END_REF]. Recently, Kessler and colleagues reported, even in adults, significant associations of "virtually all temporally primary lifetime disorders predicting subsequent onset of other disorders" in a study of lifetime comorbidity [START_REF] Kessler | Development of lifetime comorbidity in the world health organization world mental health surveys[END_REF].

Secondly, the question of a multiple testing problem must be discussed. We studied the effect of several related risk factors on child emotional and behavioural problems. However, the tests do not constitute independent hypotheses. Hence we did not adjust for multiple testing. If we, however, would apply a Bonferroni correction, the corrected alpha for chance is 0.05/10= 0.005 which would not change the interpretation of our findings. The p-values of the significant associations of postnatal parental hostility and child problems presented in table 3 and table 4 are smaller than 0.001. Moreover, appendix table 2 and 3 present additional analyses of syndrome scales that further explore the results obtained with the broadband scale Internalizing and Externalizing. Hence, the aim here was not to test more hypotheses, but to explain the results observed.

The present study has several strengths. First, both mother and father participated in this study, and thus information about depressive symptoms, hostility and family functioning of both parents was available. This enabled us to study maternal and paternal effects on child development separately. Second, child emotional and behavioural problems were assessed separately by mother and father. Using multiple informants increased the reliability of our findings, and reduced the risk of reporter bias. Since assessment of behaviour will always be subjective, reporter bias may occur if, for instance, a depression of the mother influences her view on her child's behaviour [START_REF] Fergusson | The effect of maternal depression on maternal ratings of child behavior[END_REF]. Third, our study was embedded in a large birth cohort, which made it possible to adjust for numerous confounders. Besides these strengths, this study has also limitations. First, our response analyses showed that selection occurred toward well functioning families with a higher social economic status (SES). As partner participation is higher in families with higher SES, our study was prone to represent more well functioning families [START_REF] Costigan | children with Internalizing Problem scores below the 80 th percentile on the Child Behavior Checklist. $ Model 1; prenatal depressive symptoms score of mother and father, Model 2; model 1 + prenatal symptoms of hostility score of mother and father, Model 3; model 2 + prenatal family functioning reported by mother and father, Model 4; model 3 + postnatal depressive symptoms score of mother and father, Model 5; model 4 + postnatal symptoms of hostility score of mother and father[END_REF]. Second, observational measurements in this large cohort were not feasible. Therefore, we relied on report of mothers and fathers on psychological symptoms, family functioning and child behaviour.

Yet, we used validated questionnaires with good reliability and validity. Third, as this study was performed in a fairly healthy population we should be careful generalizing our findings to clinical populations.

In conclusion, we found that family functioning experienced by the mother and postnatal hostile behaviour of parents independently contributed to the risk of internalizing problems in 3-year-old children.

Parental postnatal hostile behaviour was also related to child externalizing problems. Interestingly, parental hostility accounted for the effect of parental depressive symptoms on child internalizing and externalizing problems. These findings suggest that prevention and intervention strategies should focus on psychological symptoms of both mothers and fathers, in particular on hostile behaviour, in families with young children.

  . All children were born between April 2002 and January 2006. The study has been approved by the Medical Ethics Committee of the Erasmus Medical Center, Rotterdam (numbers: prenatal, MEC 198.782/2001/31 and postnatal, MEC 217.595/2002/202). Written informed consent was obtained from all adult participants.

  1.14-1.54, p-values <0.01) and child externalizing problems (OR range 1.06-1.38, p-values <0.01). The other prenatal BSI subscale scores of the mother also predicted child internalizing problems (OR of Phobic Anxiety 1.18, OR of Paranoid Ideation 1.24, OR of Psychoticism 1.26, OR of Interpersonal Sensitivity 1.30, OR of Anxiety 1.34, OR of Obsessive-Compulsive 1.37, all p-values <0.001) and child externalizing problems (OR of Phobic Anxiety 1.15, OR of Paranoid Ideation 1.23, OR of Psychoticism 1.21, OR of Interpersonal Sensitivity 1.27, OR of Anxiety 1.22, OR of Obsessive-Compulsive 1.42, all p-values <0.01.

Table 1 Subject characteristics (n=2698) Child Internalizing Problems reported by both parents low internalizing problems $ high internalizing problems $

 1 Low internalizing problems were defined as scores below the 80 th percentile on the Internalizing scale of the Child Behavior Checklist and High internalizing problems as scores at the 80 th percentile and higher on the Internalizing scale of the Child Behavior Checklist. $ mean (standard deviation) unless otherwise indicated # median (100% range)¶ with the chi-square statistic for categorical variables (parental education, smoking during pregnancy, alcohol during pregnancy, gender, child ethnicity), the independent t-test for normally distributed continuous variables (parental age, birth weight) and the Mann Whitney U test for non-normally distributed continuous variables (gestational age).

	(n=2162)	(n=536)	test statistic	p-value ¶

Table 2 The associations of parental symptoms of psychopathology and prenatal family functioning with child emotional and behavioural problems as reported by both parents.

 2 Reference group = children with Internalizing Problem scores/ Externalizing Problem scores below the 80 th percentile on the Child Behavior Checklist. All analyses were adjusted for child gender, birth weight, birth order, ethnicity, child age at questionnaire, maternal smoking and alcohol use during pregnancy, parental age and parental educational level. Small differences in numbers due to the exclusion of outliers in postnatal psychological symptoms. Abbreviations: OR; odds ratio, CI; confidence interval *OR's represent the increased risk of internalizing and externalizing problem scores per standard deviation (sd) increase of the determinants.

			Child Internalizing Problems at 3yrs.		Child Externalizing Problems at 3yrs.
			reported by both parents (per sd)			reported by both parents (per sd)
		OR *	95% CI	p-value	OR *	95% CI	p-value
	Prenatal depressive symptoms per sd
	(n=2698)
	Mother	1.21	1.11;1.32	<0.001	1.23	1.13;1.34	< 0.001
	Father	1.18	1.08;1.29	<0.001	1.16	1.060;1.26	0.001
	Prenatal hostility symptoms per sd
	(n=2698)
	Mother	1.27	1.16;1.39	<0.001	1.29	1.18;1.41	<0.001
	Father	1.23	1.13;1.34	<0.001	1.23	1.13;1.34	<0.001
	Prenatal family functioning per sd
	(n=2698)
	Mother	1.14	1.04;1.25	<0.001	1.24	1.13;1.36	<0.001
	Father	1.18	1.07;1.30	0.001	1.19	1.08;1.31	0.001
	Postnatal depressive symptoms per sd
	(3yrs.after birth)(n=2692)
	Mother	1.37	1.25;1.50	<0.001	1.32	1.21;1.44	<0.001
	Father	1.24	1.14;1.35	<0.001	1.26	1.16;1.37	<0.001
	Postnatal hostility symptoms per sd
	(3yrs. after birth)(n=2696)
	Mother	1.54	1.40;1.69	<0.001	1.51	1.38;1.66	<0.001
	Father	1.42	1.30;1.55	<0.001	1.44	1.32;1.57	<0.001

Table 3 The association of family functioning and parental psychopathology with child internalizing problems as reported by both parents in mutually adjusted successive models. Child Internalizing Problems at 3yrs. reported by both parents (per sd)

 3 Reference group = children with Internalizing Problem scores below the 80 th percentile on the Child Behavior Checklist. $ Model 1; prenatal depressive symptoms score of mother and father, Model 2; model 1 + prenatal symptoms of hostility score of mother and father, Model 3; model 2 + prenatal family functioning reported by mother and father, Model 4; model 3 + postnatal depressive symptoms score of mother and father, Model 5; model 4 + postnatal symptoms of hostility score of mother and father. All reported per standard deviation to facilitate the comparison of these measurements. All analyses were adjusted for child gender, birth weight, birth order, ethnicity, child age at questionnaire, maternal smoking and alcohol use during pregnancy, parental age and parental educational level. Only mutually adjusted results are reported. Small differences in numbers due to the exclusion of outliers in postnatal psychological symptoms.

		model 1		model 2		model 3		model 4		model 5 $
	Successive	(n=2698)		(n=2698)		(n=2698)		(n=2687)		(n=2685)
	models	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p
	Prenatal depressive symptoms per sd
	mother	1.18 1.08;1.29 <0.001 1.07 0.96;1.19 0.23	1.04 0.93;1.16 0.49	1.01 0.90;1.13 0.75	1.06 0.94;1.19 0.36
	father	1.15 1.05;1.26 0.002 1.07 0.96;1.19 0.22	1.05 0.94;1.17 0.33	1.01 0.92;1.13 0.74	1.04 0.93;1.16 0.52
	Prenatal hostility symptoms per sd
	mother				1.18 1.05;1.32 0.004 1.15 1.02;1.29 0.02	1.12 1.00;1.26 0.07	1.04 0.92;1.17 0.52
	father				1.15 1.04;1.28 0.008 1.14 1.02;1.27 0.02	1.13 1.01;1.26 0.03	1.06 0.95;1.19 0.31
	Prenatal family functioning per sd
	mother							1.28 1.15;1.42 <0.001 1.25 1.12;1.39 <0.001 1.23 1.10;1.37 <0.001
	father							0.99 0.89;1.11 0.92	0.97 0.87;1.08 0.65	0.96 0.83;1.05 0.51
	Postnatal depressive symptoms per sd (3yrs. after birth)
	mother										1.24 1.13;1.36 <0.001 1.07 0.96;1.20 0.28
	father										1.11 1.01;1.22 0.02	0.99 0.88;1.10 0.82
	Postnatal hostility symptoms per sd (3yrs. after birth)
	mother													1.35 1.20;1.52 <0.001
	father													1.30 1.17;1.46 <0.001
	Abbreviations: OR; odds ratio, CI; confidence interval, p; p-value
	* OR's represent the increased risk of internalizing problems per standard deviation (sd) increase of the determinants.

Table 4 The association of family functioning and parental psychopathology with child externalizing problems as reported by both parents in mutually adjusted successive models. Child Externalizing Problems at 3yrs. reported by both parents (per sd)

 4 Reference group = children with Externalizing Problem scores below the 80 th percentile on the Child Behavior Checklist. $ Model 1; prenatal depressive symptoms score of mother and father, Model 2; model 1 + prenatal symptoms of hostility score of mother and father, Model 3; model 2 + prenatal family functioning reported by mother and father, Model 4; model 3 + postnatal depressive symptoms score of mother and father, Model 5; model 4 + postnatal symptoms of hostility score of mother and father. All reported per standard deviation to facilitate the comparison of these measurements. All analyses were adjusted for child gender, birth weight, birth order, ethnicity, child age at questionnaire, maternal smoking and alcohol use during pregnancy, parental age and parental educational level. Only mutually adjusted results are reported. Small differences in numbers due to the exclusion of outliers in postnatal psychological symptoms.

		model 1		model 2		model 3		model 4		model 5 $
	Successive	(n=2698)		(n=2698)		(n=2698)		(n=2687)		(n=2685)
	models	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	P	OR *	95%CI	p
	Prenatal depressive symptoms per sd
	mother	1.19 1.09;1.30 <0.001 1.09 0.98;.1.22 0.14	1.06 0.95;1.18 0.29	1.03 0.92;1.16 0.59	1.07 0.95;1.21 0.25
	father	1.12 1.02;1.23 0.009 1.04 0.94;1.16 0.48	1.03 0.96;1.15 0.60	1.01 0.91;1.13 0.88	1.03 0.92;1.15 0.63
	Prenatal hostility symptoms per sd
	mother				1.19 1.06;1.33 0.003 1.17 1.04;1.31 0.006 1.15 1.02;1.29 0.02	1.07 0.95;1.21 0.25
	father				1.16 1.04;1.29 0.005 1.15 1.03;1.28 0.013 1.12 1.00;1.25 0.04	1.05 0.94;1.18 0.37
	Prenatal family functioning per sd
	mother							1.15 1.04;1.28 0.010 1.11 1.02;1.29 0.05	1.10 0.99;1.23 0.08
	father							1.04 0.93;1.16 0.494 1.01 0.90;1.13 0.79	1.00 0.89;1.12 0.97
	Postnatal depressive symptoms per sd (3yrs. after birth)
	mother										1.19 1.08;1.31 <0.001 1.02 0.91;1.14 0.68
	father										1.15 1.05;1.26 0.004 1.00 0.90;1.12 0.93
	Postnatal hostility symptoms per sd (3yrs. after birth)
	mother													1.34 1.20;1.50 <0.001
	father													1.33 1.19;1.48 <0.001
	Abbreviations: OR; odds ratio, CI; confidence interval, p; p-value
	* OR's represent the increased risk of externalizing problems per standard deviation (sd) increase of the determinants.

Table 1 Subject characteristics (n=2698) Child Internalizing Problems reported by both parents low internalizing problems $ high internalizing problems $

 1 Low internalizing problems were defined as scores below the 80 th percentile on the Internalizing scale of the Child Behavior Checklist and High internalizing problems as scores at the 80 th percentile and higher on the Internalizing scale of the Child Behavior Checklist. with the chi-square statistic for categorical variables (parental education, smoking during pregnancy, alcohol during pregnancy, gender, child ethnicity), the independent t-test for normally distributed continuous variables (parental age, birth weight) and the Mann Whitney U test for non-normally distributed continuous variables (gestational age).

	(n=2162)	(n=536)	test statistic	p-value ¶

$ mean (standard deviation) unless otherwise indicated # median (100% range) ¶

Table 2 The associations of parental symptoms of psychopathology and prenatal family functioning with child emotional and behavioural problems as reported by both parents.

 2

			Child Internalizing Problems at 3yrs.		Child Externalizing Problems at 3yrs.
			reported by both parents (per sd)			reported by both parents (per sd)
		OR *	95% CI	p-value	OR *	95% CI	p-value
	Prenatal depressive symptoms per sd
	(n=2698)
	Mother	1.21	1.11;1.32	<0.001	1.23	1.13;1.34	< 0.001
	Father	1.18	1.08;1.29	<0.001	1.16	1.060;1.26	0.001
	Prenatal hostility symptoms per sd
	(n=2698)
	Mother	1.27	1.16;1.39	<0.001	1.29	1.18;1.41	<0.001
	Father	1.23	1.13;1.34	<0.001	1.23	1.13;1.34	<0.001
	Prenatal family functioning per sd
	(n=2698)
	Mother	1.14	1.04;1.25	<0.001	1.24	1.13;1.36	<0.001
	Father	1.18	1.07;1.30	0.001	1.19	1.08;1.31	0.001
	Postnatal depressive symptoms per sd
	(3yrs.after birth)(n=2692)
	Mother	1.37	1.25;1.50	<0.001	1.32	1.21;1.44	<0.001
	Father	1.24	1.14;1.35	<0.001	1.26	1.16;1.37	<0.001
	Postnatal hostility symptoms per sd
	(3yrs. after birth)(n=2696)
	Mother	1.54	1.40;1.69	<0.001	1.51	1.38;1.66	<0.001
	Father	1.42	1.30;1.55	<0.001	1.44	1.32;1.57	<0.001

Table 3 The association of family functioning and parental psychopathology with child internalizing problems as reported by both parents in mutually adjusted successive models. Child Internalizing Problems at 3yrs. reported by both parents (per sd)

 3

		model 1		model 2		model 3		model 4		model 5 $
	Successive	(n=2698)		(n=2698)		(n=2698)		(n=2687)		(n=2685)
	models	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p
	Prenatal depressive symptoms per sd
	mother	1.18 1.08;1.29 <0.001 1.07 0.96;1.19 0.23	1.04 0.93;1.16 0.49	1.01 0.90;1.13 0.75	1.06 0.94;1.19 0.36
	father	1.15 1.05;1.26 0.002 1.07 0.96;1.19 0.22	1.05 0.94;1.17 0.33	1.01 0.92;1.13 0.74	1.04 0.93;1.16 0.52
	Prenatal hostility symptoms per sd
	mother				1.18 1.05;1.32 0.004 1.15 1.02;1.29 0.02	1.12 1.00;1.26 0.07	1.04 0.92;1.17 0.52
	father				1.15 1.04;1.28 0.008 1.14 1.02;1.27 0.02	1.13 1.01;1.26 0.03	1.06 0.95;1.19 0.31
	Prenatal family functioning per sd
	mother							1.28 1.15;1.42 <0.001 1.25 1.12;1.39 <0.001 1.23 1.10;1.37 <0.001
	father							0.99 0.89;1.11 0.92	0.97 0.87;1.08 0.65	0.96 0.83;1.05 0.51
	Postnatal depressive symptoms per sd (3yrs. after birth)
	mother										1.24 1.13;1.36 <0.001 1.07 0.96;1.20 0.28
	father										1.11 1.01;1.22 0.02	0.99 0.88;1.10 0.82
	Postnatal hostility symptoms per sd (3yrs. after birth)
	mother													1.35 1.20;1.52 <0.001
	father													1.30 1.17;1.46 <0.001

Table 4 The association of family functioning and parental psychopathology with child externalizing problems as reported by both parents in mutually adjusted successive models. Child Externalizing Problems at 3yrs. reported by both parents (per sd)

 4 Prenatal hostility symptoms per sd mother 1.19 1.06;1.33 0.003 1.17 1.04;1.31 0.006 1.15 1.02;1.29 0.02 1.07 0.95;1.21 0.25 father 1.16 1.04;1.29 0.005 1.15 1.03;1.28 0.013 1.12 1.00;1.25 0.04 1.05 0.94;1.18 0.37

		model 1		model 2		model 3		model 4		model 5 $
	Successive	(n=2698)		(n=2698)		(n=2698)		(n=2687)		(n=2685)
	models	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	p	OR *	95%CI	P	OR *	95%CI	p
	Prenatal depressive symptoms per sd
	mother	1.19 1.09;1.30 <0.001 1.09 0.98;.1.22 0.14	1.06 0.95;1.18 0.29	1.03 0.92;1.16 0.59	1.07 0.95;1.21 0.25
	father	1.12 1.02;1.23 0.009 1.04 0.94;1.16 0.48	1.03 0.96;1.15 0.60	1.01 0.91;1.13 0.88	1.03 0.92;1.15 0.63
	Prenatal family functioning per sd
	mother							1.15 1.04;1.28 0.010 1.11 1.02;1.29 0.05	1.10 0.99;1.23 0.08
	father							1.04 0.93;1.16 0.494 1.01 0.90;1.13 0.79	1.00 0.89;1.12 0.97
	Postnatal depressive symptoms per sd (3yrs. after birth)
	mother										1.19 1.08;1.31 <0.001 1.02 0.91;1.14 0.68
	father										1.15 1.05;1.26 0.004 1.00 0.90;1.12 0.93
	Postnatal hostility symptoms per sd (3yrs. after birth)
	mother													1.34 1.20;1.50 <0.001
	father													1.33 1.19;1.48 <0.001

Acknowledgements

The Generation R Study is conducted by the Erasmus Medical Centre in close collaboration with the Erasmus University Rotterdam, School of Law and Faculty of Social Sciences, the Municipal Health Service Rotterdam area, Rotterdam, the Rotterdam Homecare Foundation, Rotterdam, and the Stichting Trombosedienst & Artsenlaboratorium Rijnmond (STAR), Rotterdam. We gratefully acknowledge all participants and the contribution of general practitioners, hospitals, midwives and pharmacies in Rotterdam. The first phase of the Generation R Study is made possible by financial support from: Erasmus Medical Centre, Rotterdam, Erasmus University Rotterdam and the Netherlands Organization for Health Research and Development (ZonMw).

The present study was supported by a grant from the Sophia Foundation for Scientific Research (SKZ Foundation) (grant no.491) and ZonMw (grant no.10.000.1003).

Conflict of interest

The authors declare no conflict of interest. Prof. Dr. F.C. Verhulst is a contributing author of the Achenbach System of Emperically Based Assessments, from which he receives remuneration.