Dr Arnold Lohaus
email: arnold.lohaus@uni-bielefeld.de

Stress Prevention in Adolescence: Evaluation of a Multimodal Training Approach

Keywords: Stress Prevention, Adolescence, E-learning, Evaluation

Subject and Aims. This paper reports on the development and evaluation of a stress prevention program for adolescents of grades 8 and 9. The program is based on the problem-solving approach and was developed on the basis of several evaluation studies. It consists of eight weekly training sessions with durations of 90 minutes each and is accompanied by an e-learning platform. Evaluation Studies. The first section of the paper reports on a preceding demand analysis and the initial development and evaluation of the stress prevention program. The second section summarizes the results of providing an additional e-learning platform. Eight online-lessons were designed in correspondence to the training sessions of the face-to-face intervention. The last section of the paper focuses on the results of an evaluation of an optimized training version including the successful elements of the face-to-face and the elearning platform. Results and Conclusion. The results of the final evaluation study showed clear knowledge and self-efficacy improvement and reduction of stress symptoms. Moreover, the training led to positive assessments by most adolescents. Possible actions in contributing to an increase of the training effects beyond those already apparent in the current evaluation studies are discussed additionally.

Introduction

Adolescents are an important target group for health promotion and for the promotion of somatic and psychological well-being. They are confronted with several major developmental tasks that require readjustments (like achieving emotional independence from parents or achieving new relations with peers of both genders; [START_REF] Kaplan | A child's odyssey. Child and adolescent development[END_REF][START_REF] Mcnamara | Stress in young people. What's new and what can we do? Continuum[END_REF]. It is thus important to develop appropriate strategies for coping with these new demands. It is also important to avoid the development of inappropriate coping strategies for solving problems (like substance use in dealing with disappointments). Because many coping strategies are established and stabilized during adolescence, this age group can be seen as a core target group for health promotion [START_REF] Currie | Health and health behaviour among young people. Issue 1 of the WHO Policy Series: Health policy for children and adolescents. World Health Organization[END_REF].

On the other hand, adolescents form a rather difficult target group for health promotion activities, because many adolescents feel well at the present time and do not see the necessity of promoting their coping behavior to be better adjusted in the future. Moreover, adolescents often show an unrealistic optimism regarding their susceptibility to health problems [START_REF] Weinstein | Unrealistic optimism about susceptibility to health problems[END_REF][START_REF] Weinstein | Unrealistic optimism about susceptibility to health problems: Conclusions from a community-wide sample[END_REF]. This means that they feel less vulnerable to health problems than others, with the consequence that they are less motivated to care about health promotion activities.

This paper reports on the development of a stress prevention program to promote the coping behavior of adolescents. The program was based on a preceding demand analysis in order to focus on topics and problems seen as relevant by the target group. Moreover, an additional e-learning platform was provided to increase the motivation of the participating adolescents. Thus, several actions were taken to increase the interest and motivation of adolescents to participate in the program. The first section of this paper reports on a demand analysis and the initial development and evaluation of the stress prevention program. The following section summarizes the results of providing an additional e-learning platform, while the last sections focus on the results of an optimized training version including the successful elements of the preceding evaluation studies.

Demand analysis and initial development of a stress prevention training for adolescents

Before constructing the stress prevention program a demand analysis was conducted to gather information about the willingness of adolescents to participate in such a program and about possibilities to increase their motivation. A total of 1699 children and adolescents of grades 5 to 10 participated in the demand analysis. The results showed that between 25% and 50% of the children and adolescents were interested in participating in a stress prevention program, depending on age and gender. The main influential variable was gender, indicating a lower interest in boys as compared to girls. The demand analysis also showed a preference for the school setting as the preferred location for stress prevention training. The selection of topics seen as relevant by the adolescents, the inclusion of diversified activities in the program and the use of innovative methodologies were also evaluated as being important. These preferences were taken into consideration for the construction of the training program.

In consequence, a stress prevention program to be used in school settings was developed. The school setting was not only selected because it was in line with the adolescents' preferences, but also because it provides the opportunity to reach all adolescents and not only those specifically interested in stress prevention. The stress prevention program is characterized by a modular structure with a basic module provided for all adolescents and Stress Prevention in Adolescents 4 three additional modules which can be selected to fit the demands of the specific target group. All modules consist of four sessions of 90 minutes each. Typically, the basic module is combined with one of the additional modules leading to eight sessions for the participating adolescents. The main target groups are adolescents of grade 8 and 9.

Description of basic and additional modules

The basic module focuses mainly on a problem-solving approach. The aim is that adolescents do not solve problems spontaneously, but that they first consider possible options for action in problematic situations. The typical steps in a problem-solving approach are (a) to analyse the problem, (b) to search for possible solutions, (c) to identify the advantages and disadvantages of each solution, (d) to execute the optimal solution and (e) to evaluate the results (D'Zurilla & Goldfried 1971). The adolescents train using this approach on the basis of provided and self-selected problems. The basic module also provides knowledge about stress, stress symptoms and possible coping strategies.

The additional modules are related to (a) cognitive reconstruction, (b) seeking social support and (c) relaxation and time management. Theoretically, problem solving is a meta-strategy to cope with problems, while the additional modules focus on specific strategies (like using relaxation) to be used as specific solutions in the problem solving process. This was the reason for focussing on the problem solving approach as a basic strategy in the basic module.

The additional module on cognitive reconstruction focuses on the relation between thoughts and stress. It contains training elements to stimulate a more positive evaluation of stress-evoking situations and also a more positive self-evaluation. An enhanced self-evaluation may be supportive in being able to see problematic situations in a more positive light.

The additional module on seeking social support is related to mobilizing social support in the case of experienced problems. The focus is not only on support by family or peer group members, but also on institutional support and the search for institutions that may provide support for adolescents. This module focuses also on the promotion of social competencies, because social competencies increase the likelihood of getting social support.

The additional module on relaxation and time management focuses on keeping calm and relaxed as a coping strategy. Therefore, relaxation techniques are introduced to the adolescents, but also techniques to enhance their time management. In the case of relaxation, the Progressive Muscle Relaxation is introduced as a systematic relaxation technique. However, unsystematic methods of relaxation (e.g. listening to music or having fun) are also addressed in this module. Moreover, the adolescents are acquainted with time management techniques.

The program was evaluated in a sample of 461 adolescents of grades 8 to 9. All combinations of the basic module with each of the additional program modules were compared. A control group without intervention was also included (339 adolescents). Results showed a significant increase in knowledge about stress and coping across all combinations. In addition, more positive thoughts were reported in stress situations and the reported coping behavior changed in the intended direction. There were, however, no effects on the number of reported

Stress Prevention in Adolescents 5

stress symptoms. There were differences between the training combinations showing the most favorable results for cognitive reconstruction and seeking social support. The least favorable results were found for relaxation and time management [START_REF] Beyer | Stresspräventionstraining im Jugendalter[END_REF].

Effects of providing an additional e-learning platform

Although stress management is a relevant topic for adolescents, the motivation to participate in a stress management program is often weak. On the other hand, adolescents often show high interest in the use of innovative media like the internet [START_REF] Rideout | Generation M: Media in the lives of 8-18 year-olds[END_REF]. This was the reason to analyse whether internet-based e-learning in the context of a stress prevention program produced additional effects. Online interventions are characterized by high accessibility as well as interactivity [START_REF] Taylor | The use of the Internet to provide evidence-based integrated treatment programs for mental health[END_REF]. Moreover, low thresholds for participation as well as anonymity are important advantages of internet-delivered mental health promotion [START_REF] Taylor | The use of the Internet to provide evidence-based integrated treatment programs for mental health[END_REF].

The e-learning platform provided additional contents related to the training. The online-lessons were released weekly during the intervention period and could be used by the adolescents in addition to the face-to-face training. 267 adolescents in grade 7 and 8 participated in the stress prevention program described above. 127 of these adolescents were additionally offered the opportunity to use an e-learning website. An additional 91 adolescents participated in a control group without training. Before and after the training interval, all adolescents were questioned about their knowledge regarding stress and coping. In addition, they had to assess their perceived stress vulnerability, their coping behavior and their stress symptomatology (one week before and one week after as well as two months after the training). The training groups were also asked about their satisfaction with the training.

The results indicate a knowledge increase in the training groups which was stable over time (across two months).

The increase was higher in the training group with e-learning than in the group without. Moreover, training satisfaction increased if additional internet support was available. There were, however, no effects on distal variables like assessed stress vulnerability, coping behavior and stress symptomatology [START_REF] Fridrici | Sind Jugendliche "online" besser zu erreichen? Zur Internetnutzung bei Stresspräventionsmaßnahmen für Jugendliche[END_REF]. The results show that it is possible to increase the effects of a stress prevention program in adolescents by supplying additional training contents via e-learning. It is worth noting that also the satisfaction with the training could be increased which may indicate that it was possible to enhance the motivation to participate in the training.

The positive additional effects of the e-learning platform led to the question if it would be possible to replace the classical face-to-face training by an internet based training. Face-to-face training programs require a lot of personnel or time resources and it may thus be difficult to implement them in schools. Thus, an additional study focused on the comparison of the effects of a face-to-face versus an internet based e-learning platform (Fridrici & Lohaus 2009). A total of 904 adolescents in grades eight and nine was assigned to different treatment conditions (online-training, school-based face-to-face training, control group without intervention). Before and after the training interval, all adolescents were questioned about their knowledge regarding stress and coping and their appraisal of stress-evoking situations. Moreover, the participants had to assess their perceived stress vulnerability, their coping behavior and their stress symptomatology. The training groups were additionally Stress Prevention in Adolescents 6 questioned about their training acceptance. The results showed a considerable knowledge gain for participants of the online-program. Moreover, the number of positive cognitions in stress-evoking situations increased.

However, the overall effects were lower than those in the face-to-face intervention. Regarding training acceptance, the best results were obtained for participants of the face-to-face intervention. In conclusion, webbased prevention or health promotion seems to be no equivalent alternative for school-based face-to-face programs, because neither its effectiveness nor its acceptance among the adolescents is sufficient to substitute a well-implemented face-to-face intervention. Although online-prevention cannot completely substitute schoolbased face-to-face-training it may, however, be seen as an effective complement to conventional methods of health promotion.

Effects of an optimized training version

As a result of the previous studies, an optimized training version was developed that combined successful elements of the face-to-face training with the e-learning approach. The optimized training version included the basic module from the face-to-face training and additionally those training elements from the other modules that had proved to be of value in the previous evaluation studies [START_REF] Lohaus | Stressprävention im Jugendalter: Effekte eines optimierten Trainingsprogramms mit Internetbegleitung[END_REF] The data of this study were reanalysed to examine whether the assumptions of the Transtheoretical Model (TTM; [START_REF] Prochaska | The Transtheoretical Model of health behavior change[END_REF][START_REF] Velicer | Smoking cessation and stress management: Applications of the Transtheoretical Model of behavior change[END_REF]) may be useful in evaluating the effectiveness of a stress prevention program in adolescence to promote appropriate coping behaviour [START_REF] Vierhaus | Effects of a stress prevention program addressing adolescents in different phases of behaviour change[END_REF]. The TTM assumes a movement through a series of phases in the adoption or cessation of behaviour patterns (precontemplation, contemplation, preparation, action and maintenance). It was therefore expected that program participation is associated with a progression through the phases. The results of the reanalysis indicate that the program participation is indeed associated with a progression in phases (although this effect was not stable). Besides this, adolescents in different phases benefit from participation differentially.

The conclusion is that a systematic promotion in the different phases of behaviour change by integrating TTMtailored "tools" into a stress management program may improve participants' intention and competence to actually show appropriate coping behaviour.

Conclusion

Stress Prevention in Adolescents 7

The results of the evaluation studies show that it is possible to improve the stress management capabilities of adolescents. It is worth noting that the effects are largely independent of gender, although boys were initially less interested in participating in a stress management program than girls. The most favourable results could be achieved by face-to-face training in combination with an e-learning approach. The additional positive effects of an internet platform on training satisfaction show the importance of actions to increase the motivation and interest of adolescents. As the reanalysis of the data of the final study shows, it may also be useful to construct stage-oriented programs to be in line with the requirements of specific stages in a process of health promotion.

To enhance the motivation of adolescents, it could additionally be important to focus on immediate effects of stress management training, because adolescents are typically not interested in effects that are merely perceivable far in the future. It could also be helpful to use incentives (like participation in a raffle etc.) to increase the motivation and interest of adolescents in health promotion activities [START_REF] Fridrici | Effects of incentives in web-based prevention for adolescents: Results of an exploratory field study[END_REF]. To stabilize the effects of health promotion it could be important to include additional booster sessions to remind participants of the program contents. It would also be helpful to integrate standardized programs in a broader context of health promoting activities. The consequence would be that the program effects are not isolated but part of a broader set of activities which could additionally help to stabilize the effects (for example in the context of health-promoting schools).

  . The optimized training version consisted of eight weekly training sessions with durations of 90 minutes each and was accompanied by an e-learning platform. 372 adolescents participated in this study. 182 of them participated in the program, while 190 were allocated to the control group. Evaluation criteria were related to changes in the knowledge about stress and coping, stress vulnerability, experience of stress symptoms and self-efficacy. Additional items were related to the evaluation of the training. The evaluation took place one week before, one week after and two months after the training. The results showed clear knowledge and clear self-efficacy improvements and significant reductions regarding stress symptoms. The training led to positive assessments by most adolescents which were significantly more positive than for the initial training version. It is also interesting to note that it was possible to achieve stress symptom reductions which were not possible with the initial version. Thus, the optimized training version indeed led to the intended additional improvements.

Acknowledgements

This study was supported by the German Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung) and by a Health Insurance Company (Techniker Krankenkasse).

Conflict of interest

The author declares that there is no conflict of interest.


Matthias Franz
email: matthias.franz@med.uni-duesseldorf.de

Lonja Weihrauch

Ralf Schäfer

PALME: A preventive parental training program for single mothers with preschool aged children

Keywords: single mothers, prevention, parental training program, maternal depression, child behaviour, PALME

Aim: Single mothers are exposed to various psychosocial risks. They suffer more frequently from chronic diseases, depression and elevated stress levels. These risk factors have an impact also on their children, who display more frequently adaptation or behaviour problems. Thus, it was aimed to develop an efficient parental training program designed for the needs and problems of single mothers and their preschool aged children. The concept of PALME is based on attachment theory and psychodynamic-interactional approaches. The 20 weekly sessions of the program are manualised and follow a modular structure. It is guided by a couple (f/m) of trained kindergarten teachers. Subjects and Methods: The efficacy of the program was evaluated within a randomised controlled trial. 61 complete data sets were analysed within a variance analytic model (group x time) pre and post treatment. Dependent variables for the mothers were psychological symptom load (SCL-90-R, BSS), well-being (SF-12), emotional competences (SEE), and problem behaviour (SDQ) for the children. Results: It could be shown that maternal psychological symptom load and depression were reduced by the training, while maternal well-being and emotional competences were enhanced. Dependent from the intervention the children showed a tendency towards reduced problem behaviour.

Conclusion:

The PALME program is suited for the prevention of maternal depression and for enhancing emotional competences of single mothers. Because of its benefits, low costs, easy implementation and good acceptance by the mothers it was implemented as regular help offer in many German communities.

Theoretical background

Numerous studies have demonstrated that single mothers suffer from a clearly worse socioeconomic status [START_REF] Helfferich | Gesundheit alleinerziehender Mütter und Väter. Gesundheitsberichterstattung des Bundes[END_REF]Musick und Mare 2006;[START_REF] Spencer | Does material disadvantage explain the increased risk of adverse health, educational, and behavioral outcomes among children in lone parent households in Britain? A cross sectional study[END_REF][START_REF] Franz | Langzeitfolgen von Trennung und Scheidung[END_REF]), but also from heightened mental stress levels and more often from depressive disorders than partnered mothers [START_REF] Weitoft | Mortality among lone mothers in Sweden. A population study[END_REF]Franz et al. 2003;[START_REF] Cairney | Stress, social support and depression in single and married mothers[END_REF][START_REF] Wang | The differences between single and married mothers in the 12-month prevalence of major depressive syndrome, associated factors and mental health service utilization[END_REF][START_REF] Loxton | The psychological health of sole mothers in Australia[END_REF]. In general, maternal depression can impair the parental perception of the children's needs and the empathy for the children's actual emotional state and thus restrain the infant development [START_REF] Luoma | Longitudinal Study of Maternal Depressive Symptoms and Child Well-Being[END_REF][START_REF] Mclearn | The timing of maternal depressive symptoms and mothers' parenting practices with young children. implications for pediatric practice[END_REF].

For this reason the statistically heightened depression of single mothers constitutes a risk factor also for the development of the child, especially if compensatory influences are missing. For children of single parent families an impaired social development, increased risks for psychological disorders and an impaired school achievement were reported [START_REF] Helfferich | Gesundheit alleinerziehender Mütter und Väter. Gesundheitsberichterstattung des Bundes[END_REF][START_REF] Cherlin | The long-term effects of parental divorce on the mental health of young adults. A developmental perspective[END_REF][START_REF] Mclanahan | (ed) Coping with divorce, single parenting, and remarriage. A risk and resiliency perspective[END_REF][START_REF] Sadowski | Early life family disadvantages and major depression in adulthood[END_REF][START_REF] Lipman | Child well-being in single-mother families[END_REF][START_REF] Gilman | Family disruption in childhood and risk of adult depression[END_REF][START_REF] Weitoft | Mortality, severe morbidity, and injury in children living with single parents in Sweden. A population-based study[END_REF]Franz et al. 2003;[START_REF] Franz | Langzeitfolgen von Trennung und Scheidung[END_REF][START_REF] Hagen | Gesundheit von Kindern alleinerziehender Mütter[END_REF].

The PALME program

PALME1 is a structured manualised preventive group intervention for psychosocial impaired single mothers with preschool aged children (3-6 years) developed by an interdisciplinary team of physicians, psychologists and educators. A PALME group consists of 12 up to 14 mothers and two trained group leaders (m/f) who have a moderating and demonstrating function. Based on attachment theory and psychodynamic-interactional approaches the program focuses on the strengthening of intuitive parental competences like empathy and the sensitive perception of the child's needs. Further it aims at the evolvement of social skills in dealing with own partnership conflicts and parental responsibility.

Central aims of PALME

One of the central goals of PALME is the reduction of maternal depression to enable the mothers to empathise with the child's feelings and to mirror them in their responsive facial behaviour. The differentiating perception and empathic reflection of the child's feelings are fundamental requirements for the emotional development of the child. By the consolidation of these intuitive parental functions the mother-child-relationship should be stabilised. In addition to this focus on emotional processes PALME also includes concrete behavioural topics contributing to an effective stress managment. Because of the commonly existing conflicts of single mothers with their separated partners which often involve also the children, PALME aims at the separation of the parental responsibility and couple conflicts. Further goals of the program are to treat self-esteem problems and feelings of guilt, to detect unconscious delegations to the child (e.g. parentification) and to practice social competences.

Structure of the PALME-program

The PALME-program consists of twenty group sessions (90 minutes each), which are structured by four consecutive modules with different topics. The modules comprise four to six group sessions. The first session of PALME is reserved for warming up and clarifying rules and questions, the last session for retrospection, reflection and saying good-bye.

In the following section the contents and aims of the modules are described. The tables 1-4 provide a detailed overview of the particular modules.

Modul I: Emotion-focused self-perception of the mother

The first module focuses on the emotional self-awareness of the participants. It is based on the assumption that it is easier to empathise with the experience and needs of other persons if one is able to perceive different own emotional states. In the course of the module the mothers engage in their role demands, the perception, differentiation and articulation of their own feelings, but also in their self-esteem and their personal strengths and weaknesses based on their biographical backgrounds.

[please insert table 1 here]

Modul II: Empathy and perspective taking to the emotional experience and the developmental needs of the child In the second module the mothers deal with the different needs of their children, most notably with their need for attachment/security and exploration/encouragement. The mothers learn about the importance of basic affects in the interpersonal regulation of these needs and how to assist the emotional exchange and development of the child. Sensitive listening and acting are exercised as basic empathic competences.

[please insert table 2 here]

Modul III: Perception of the family situation

In the third module the situation of the family system is considered. The importance of the father in general, the relationship to their own fathers of the mothers, the contact to the father of the child and the separation experience are picked out as central themes. In this module also the separation of the couple's conflict and the parental responsibility is a central issue.

[please insert table 3 here]

Modul IV: Goal-oriented development of social skills in the daily routine

The fourth module is more related to concrete behaviour than the other modules.

It aims at the acquisition of behaviour patterns that help to prevent stress overload.

The participants learn how to handle stress and conflict situations, also exercises to strengthen the ability to enjoy are carried out.

[please insert table 4 here]

Structure of a PALME session

Besides this modular structure of the program the individual sessions have a fixed course of action. Every session starts with a short input, wherein the participants report about their emotional state and their past week. Subsequently the participants are instructed to conduct several exercises related to the theme of the session. These exercises are carried out individually, as couples, as working teams, or as group all together. Thereby a variety of methods is used, e.g. brainstorming, group dynamic role plays, guided imaginations in relaxation and sensomotor exercises. All group dynamic exercises or role plays aim at the empathic perspective taking and identification of the mothers with the needs of their children by activating and mobilising authentic emotions within the interactional group process. For some exercises especially designed didactic material exists like playing cards or worksheets to enrich the exercises and reduce the expended effort for the group leaders. At the end of each session the mothers get a leaflet with theoretical information about the topic as reminder and to enable them to rework the session. In addition, the mothers are instructed to perform exercises at home independently. These exercises serve to deepen the contents of the antecedent group session and to experience them practically. Most of these weekly exercises are arranged to support mothers and their children doing something together in cooperation and to intensify the contact between mother and child. In the next group session the experiences of the mothers with the mother-child exercises are discussed.

The PALME manual

To ensure adherence, and a constant high quality of the PALME group sessions and to facilitate the work of the group leaders the PALME program was published as a detailed manual [START_REF] Franz | PALME -Präventives Elterntraining für alleinerziehende Mütter geleitet von Erzieherinnen und Erziehern[END_REF]. Thereby, the group leaders get information about the theoretical background, the course of action and the exact organisation of each PALME session. The procedure of each exercise is described in detail to the point of concrete phrasing proposals. Nonetheless, the group leaders may adapt the program to the needs of the participants by shortening or skipping exercises, e.g. if a recent conflict rules the attention of a mother. After finishing a first version of the manual the program was tested and evaluated under naturalistic conditions in a randomised controlled trial [START_REF] Franz | PALME -Präventives Elterntraining für alleinerziehende Mütter geleitet von Erzieherinnen und Erziehern[END_REF][START_REF] Franz | Wirksamkeit eines bindungstheoretisch fundierten Elterntrainings für alleinerziehende Mütter und ihre Kinder: PALME[END_REF].

Training of the group leaders

The PALME groups are intended to be conducted by a male and a female kindergarten teacher. This couple is an essential feature of the PALME groups, because it helps the participating mothers, who mostly suffer from a recent

Implementation and evaluation of PALME Method

After pilot-testing of the PALME concept in the university context it was implemented and evaluated within a randomised, controlled trial in two German cities. For implementation within the communal setting, steering committees consisting of members of the youth welfare office and the research team were established. Information sessions for directors and employees of day care centres were organised. This should enable the employees to present PALME in their institutions and to address potential participants confidentially and personally in order to make it easier for the mothers to take part. In addition, interested educators were obtained as PALME group leaders. To reach single mothers and motivate them to take part in PALME, information material like flyers and posters were presented in the cooperating day care centres. Furthermore information packs including a registration form and screening questionnaires to inquire actual burdens and risk factors were allocated by the educators in the day care facilities.

Concurrently media reports advert to PALME.

Sample recruitment

By this procedure in both cities 127 single mothers could be interested for a participation in the study. They were screened of fulfilling the participation criteria. These were: biological mothers of preschool children aged 3-6 years, single mothers (separated from the biological father, new partnership possible), sufficient German language skills and a medium degree of psychosocial impairment. This criterion was fulfilled when mothers reached cut off values at least in one subscale of the Hospital Anxiety and Depression Scale (Hermann-Lingen et al. 2005). Mothers with an ICD-diagnosis of an addictive disorder, a serious personality disorder or another serious psychiatric disorder (surveyed with the Structured Clinical Interview for DSM-IV, Wittchen et al. 1997) were presumed to be unqualified for group participation and therefore excluded. In this case it was insured that these mothers could get qualified medical and psychological help from local clinical departments. Eighty-eight mothers met the participation criteria and were allocated by random to the intervention group (IG, N=47) and the waiting control group (CG, N=41, this group received the PALME intervention after ending of the study). The first data collection of social and psychological measures took place before intervention (t1); subsequently the mothers of IG attended once a week the 20 PALME sessions over a period of six months. Immediately after ending of the PALME groups there was a second data collection (t2). Figure 1 gives an overview of the study course.

[please insert figure 1 here]

Instruments

At t1 and t2 all participating mothers answered a detailed half-structured interview about their demographic features, biography, actual living conditions and health status. The psychometric data were collected by several standardized and proven questionnaires.

Psychological/psychosomatic stress (SCL-90-R)

The subjective impairment by physical and psychological symptoms were measured by the Symptom-Checklist-90-revised (Derogatis 1977;German version of Franke 2002) The questionnaire consists of 90 items, which are divided into 9 scales. In addition, three global parameters can be calculated. The Global Severity Index (GSI) indicates the averaged mental stress related to all 90 items. In the female population GSI-values >= 0.80 suggest a considerable psychological stress, GSI-values >= 1.58 indicate a high up to very high psychological impairment. The internal consistencies (Cronbach´s Alpha) for the 9 scales computed in a representative sample of N=2141 varied between .75 and .97. In this study, the internal consistency for the depression scale ranged from .88 to .90, the internal consistency for the GSI was .97.

Psychological well-being (SF-12)

The short form of the SF-36 Health Survey (Bullinger and Kirchberger 1998) is designed to record the health-related quality of life. It comprises 12 items and the dimensions "physical health" and "psychological health", which latter we used. In the female population the mean value for "psychological health" is 51.

Psychogenic impairment (BSS)

The Impairment-Severity-Score (German version BSS; Schepank 1995) is an expert rating procedure for the physical, psychological and social impairment for the last seven days caused by psychogenic disorders2 . The total score based on the three subscales varies between 0 and 12 points, a score > 4 is the threshold for case definition. The ratings were done by two trained graduate psychologists based on a clinical interview. The interrater reliability ranged between .89 and .99 for the total score.

Emotional competences (SEE)

The 42 items of the Scales on the Experience of Emotions (German version SEE, Behr and Becker 2004) measure an individual's style of experiencing, appraising and handling own subjective feelings. The questionnaire is structured into 7 subscales. Two scales were especially relevant in this study: "acceptance of own emotions" and "experience of emotional overflow". Scores< 19 (T=41) on the scale "acceptance of the own emotions" are classified as below average, scores > 25 (T=60) on the scale "experience of emotional overflow" are above average. In a sample of N=772 good up to very good internal consistency scores of .70 up to .86 could be obtained. In this study internal consistencies between .79 and .88 were computed for the both scales.

Child behaviour (SDQ)

Behavioural problems of the children were measured by the Strengths and Difficulties Questionnaire (SDQ, German version of Klasen et al. 2000). It consists of 25 items, which are divided into five subscales: "hyperactivity", "emotional problems", "problems in the interaction with peers", "behavioural problems" and "prosocial behaviour". The scores of the four problem subscales are aggregated into a "total problem score". The ratings were done by kindergarten teachers of the children (not the PALME group leaders). Total problem scores >=13 are viewed as marginal noticeable, scores > 16 as noticeable.

The internal consistency for the total problem score determined in a representative sample of N=990 children and adolescents aged between 6 and 16 years was .82.

In this investigation the internal consistencies ranged between .76 and .82.

Data analysis and statistics

The efficacy of the parental training program was investigated by computing models of univariate analyses of variance with repeated measures formed by the between subject factor group (IG, CG) and the within subject factor time (t1, t2).

The PALME program was regarded to be effective when there was a significant group x time interaction effect in favour of the intervention group. In this case the differences between mean values over the time within each group were tested by computing inner group contrasts. Before starting the intervention possible initial differences between both groups concerning the outcome variables were tested by multivariate and -in a second step -univariate analyses of variance for significance. If significant, the differences between IG and CG were adjusted by computing an analysis of covariance with the values at t1 as covariate. Frequency differences or differences of ordinal scaled data were investigated by chi square test, Fisher´s Exact test and Mann-Whitney-U-test. All data analyses were computed using SPSS (Statistical Package for Social Science 15.0, SPSS Inc.). As level of significance an error probability of p (α) < .05 (one-tailed) was defined.

Results

Sample description

Table 5 shows the demographic characteristics of the participating mothers and of the mothers who dropped out of the IG. The values of the 6 mothers who dropped out of the CG are not mentioned because of the small group size. The data analysis revealed only few significant differences between IG and CG concerning the demographic variables: Compared to IG, CG had more mothers who spoke another native language than German. Furthermore, in CG more mothers had a low school graduation and more mothers were primarily dependent from social services. The children of mothers in CG had significantly less frequently contact to their fathers. Despite randomisation there was a significant difference between IG and CG in the psychometric variables: Mothers in CG had higher mean values in the subscale "acceptance of own emotions" of the SEE than mothers of IG (F (1/57) = 6.19; p<0.05). This difference was considered in the data analysis.

Twenty-one mothers (45%) who were assigned to the IG stopped their attendance in the group intervention. Compared to IG, these mothers spoke more frequently another native language than German, had more preschool aged children and a lower school graduation. Regarding the psychometric variables there were no differences between IG and IG-Dropouts (table 6).

[please insert table 5 and table 6 here]

Outcome measures

The results of the data evaluation by repeated measures analyses of variance are listed in table 7. In the following sections the results are presented in detail.

[please insert table 7 here] Psychological/psychosomatic stress (SCL-90-R)

The values for the psychological/psychosomatic symptom load (GSI) showed a significant group x time interaction effect (F (1/59) = 7.52; p<0.01), that means that the values proceeded differentially over time in IG and CG (figure 2). In IG mean GSI values diminished from 1.01 (SD=0.52) at t1 to 0.52 (SD=0.37) at t2. This change was significant when computing inner group contrasts (F (1/25) = 25.35; p<0.001). In CG, only a slight decrease in GSI-values from 0.81 (SD=0.54) at t1 to 0.66 (SD=0.45) at t2 could be observed which was not significant (F (1/34) = 3.31; n.s.).

[please insert figure 2 here]

Depression (SCL-90-R)

With respect to maternal depression there was a significant group x time interaction effect, too (figure 3,F (1/59) = 6.10; p<0.05). At t1 the mean depression score in IG was in a critical range (1.42, SD=0.79, >T=60), at t2 the mean score was reduced about nearly the half (0.69, SD=0.58; F (1/25) = 18.99; p<0.001). In CG the mean depression value declined only from 1.17 (SD=0.75) at t1 to 0.94 (SD=0.64) at t2, this difference was not significant (F (1/34) = 3.64; n.s.).

[please insert figure 3 here]

Psychological well-being (SF12)

Consistent with the other results the group x time interaction effect for the psychological well-being is significant (F (1/59) = 6.93; p<0.05, figure 4). Before intervention the values of the psychological well-being in both groups were far below the mean of the female population (mean=51). Immediately after the intervention the value rose significantly in IG from 35.49 (SD=8.65) to 45.82 (SD=9.44; F (1/25) = 19.28; p<0.001). In CG the psychological well-being was found to be not significantly changed at t2 (40.80, SD=10.26) compared to t1 (38.86, SD=10.12; F (1/34) = 0.83; n.s.).

[please insert figure 4 here]

Emotional competence (SEE)

The "acceptance of the own emotions", which indicates the appreciation of the own feelings, evolved differentially in IG and CG over time (figure 5,F (1/57) = 12.46; p<0.01). In IG the mean scores of the acceptance of the own emotions rose significantly from t1=19.54 (SD=4.88) to t2=23.23 (SD=3.49; F (1/25) = 19.71; p<0.001). In CG there were no significant changes over time, at t1 the mean value was 22.64 (SD=4.65), at t2 it was 22.39 (SD=3.98; F (1/32) = 0.11; n.s.).

Because mean scores of IG and CG differed significantly at t1 (F (1/56) = 5.56; p<0.05), we also conducted an analysis of covariance with the t1-values as covariate and the group membership as factor and compared the t2-values between both groups. Even after controlling for t1-scores a significant group effect could be found at t2 (F (1/56) = 5.62; p<0.05).

Regarding the scale "experience of emotional overflow", there was a trend for evolving differentially over time in IG and CG (figure 6,F (1/57) = 3.95; p<0.10).

In IG the mean scores reduced significantly from t1=21.81 (SD=5.32) to t2=17.35 (SD=4.86; F (1/25) = 9.78; p<0.01). The mean score of CG remained almost the same from t1=20.15 (SD=6.71) to t2=19.06 (SD=6.65; F (1/32) = 1.18; n.s.).

[please insert figure 5 and6 here]

Psychogenic impairment (BSS)

The maternal psychogenic impairment assessed by expert ratings as sum score for the somatic, psychic, social subscales differed for IG and CG over time, too (figure 7,F (1/59) = 13,24; p<0,01).

In IG the mean total-score for the last seven days declined from 4.50 (SD=1.33) at t1 -representing a considerable impairment -to a mean value of 2.23 (SD=1.92) at t2 (F (1/25) = 30.12; p<0.001; figure 7). The impairment scores in CG did not change significantly over the measurement points. At t1 the mean value was M t1 =4.37 (SD=2.09), at t2 it was M t2 =4.17 (SD=2.55; F (1/34) = 0.27; n.s.).

[please insert figure 7 here]

Behavioural problems of the children (SDQ)

The behavioural problems estimated by the kindergarten teachers in the day care centres (not the trained PALME group leaders) tended to proceed differently in IG and CG over time (figure 8,F (1/35) = 3.07; p<0.10).

The children of mothers in IG showed significantly less behavioural problems at t2 compared with t1 (t1=7.12, SD=5.18 and t2=5.00, SD=4.11; F (1/13) = 7.26; p<0,05). The children of mothers in CG showed no significant changes in their behaviour over time (t1=7.65, SD=4.96, t2=7.57, SD=6.10; F (1/22) = 0.01; n.s.).

Unfortunately not all kindergarten teachers returned the questionnaire so that the reported results rely on the analysis of only 37 cases.

[please insert figure 8 here]

Intention-to-treat analysis

As mentioned earlier, a rather high percentage of mothers (N=21, 45%) left the intervention group after a few sessions. To assure that the outcome data were not distorted by this fact, an additional intention-to-treat-analysis (ITT) was computed. For this purpose the data of IG and CG each including dropouts were compared. Thirteen of the 21 dropped-out mothers took part in the second measurement post intervention, 8 mothers were not available. The missing data of these remaining eight mothers were replaced by the Last-Observation-Carried-Forward-method (Streiner, 2002). As can be inferred from table 8, the ITTanalysis confirmed the obtained results substantially. Merely the reduction of emotional overflow and of the behavioural problems of the children could not be validated.

[Table 8]

Discussion

As expected the mothers in IG experienced positive changes in their well-being after ending the PALME-groups. The mothers showed lower levels of psychological/psychosomatic symptom load (SCL-90-R, GSI). This improvement is congruent with the psychogenic impairment (BSS) assessed by trained experts who were not aware of the group affiliation of the mothers. The participants also had less depressive symptoms (SCL-90-R, subscale DEP) after the PALME intervention. This is an important result because a long-lasting maternal depression affects the infantile development too and increases children's risk for behavioural problems (Franz and Lensche 2003;Franz et al. 2003;[START_REF] Goodman | Maternal depression and child psychopathology: a meta-analytic review[END_REF][START_REF] Kouros | Dynamic associations between maternal depressive symptoms and adolescents' depressive and externalizing symptoms[END_REF][START_REF] Ashman | Trajectories of maternal depression over 7 years: relations with child psychophysiology and behavior and role of contextual risks[END_REF][START_REF] Foster | Current and past maternal depression, maternal interaction behaviors, and children's externalizing and internalizing symptoms[END_REF][START_REF] Trapolini | The effect of maternal depression and marital adjustment on young children's internalizing and externalizing behaviour problems[END_REF][START_REF] Riley | Mental health of children of low-income depressed mothers: influences of parenting, family environment, and raters[END_REF]). In addition, the mothers in IG reported a better psychological health (SF12) and improved emotional competences (SEE). The kindergarten teachers observed less behavioural problems (SDQ) in the children of IG-mothers. Since the kindergarten teachers were not informed about the group membership of the children's mothers, this trend cannot be explained by the expectancies of the kindergarten teachers. Unfortunately this result is based on the analysis of only 37 cases, so further investigations about this result are considered to be required. Finally, the mothers themselves evaluated the intervention program very positively (mean value 1.7 (SD=0.6) on a five-point Likert-scale with 1= very good and 5 = very bad, data range 1-3), concerning the behaviour of their children and their relationship to them. This study has also some limitations. The psychosocial impaired single mothers were preselected by means of their HADS-scores so that the sample was not representative for all single mothers. Thus, it is possible that relevant correlations were underestimated and the results cannot be transferred to all single mothers.

Other possible threads for the internal validity of the results could be a systematic dropout and different initial outcome scores in IG and CG. Except for the "acceptance of the own emotions" there were no significant differences between the original groups immediately after randomisation, between IG and IG-dropouts and between the resulting IG and CG after dropout. For the SEE subscale "acceptance of own emotions" it could be shown that the group effect at t2 persist even if data were controlled for the different initial values in IG and CG. Furthermore, most results could be replicated by an ITT analysis including the dropouts. In addition, all mothers who left the IG were rather motivated to participate further on. But mostly due to overload by interfering duties relating to work or caretaking, they were not able to organise it. All mothers regretted explicitly, that they had to withdraw from the PALME-group. Therefore, it is not probable that the positive effect in IG is caused by a selection bias leaving only highly motivated and/or less burdened mothers in IG.

There were some differences in the demographic variables between IG and CG:

Among the IG-dropouts, more mothers spoke another native language, had two or more preschool-aged children and/or had a lower school graduation. This fact underlines the statements of the dropped-out mothers, that the timing of the groups was not compatible to their other liabilities. Beyond that it can be assumed, that the mothers had also comprehension difficulties or maybe did not accept the group training program.

PALME is a unique parental training program for single mothers in Germanspeaking countries, where help offers especially designed for the needs of single mothers were missing until now. PALME is an economic, low-threshold program which is very well accepted by the mothers. Reduction of maternal depression, affect mobilisation and empathic perspective taking of the mothers may be induced by the interactional group dynamic approach of PALME. These factors are also important mediators of the improvement of infantile problem behaviour [START_REF] Garai | The relation of maternal sensitivity to children's internalizing and externalizing problems within the context of maternal depressive symptoms[END_REF][START_REF] Foster | Current and past maternal depression, maternal interaction behaviors, and children's externalizing and internalizing symptoms[END_REF], which also was influenced by PALME in our study. Behavioural and coping aspects or everyday stress management follow in second line. Because of this explicit integration of emotional and interactional group dynamic processes including the biographical background, attachment and behaviour oriented aspects, PALME -with regards to content and conceptexceeds other available parental training programs (e.g. [START_REF] Forgatch | Parenting through change: An effective prevention program for single mothers[END_REF][START_REF] Wolchik | An experimental evaluation of theory-based mother and mother-child programs for children of divorce[END_REF]Wolchik et al. ,2002;;[START_REF] Lipman | Social support and education groups for single mothers: a randomized controlled trial of a community-based program[END_REF], which are predominantly or exclusively behaviour centred. Finally the scientific evaluation using a RCTdesign demonstrated sustained effects of the program on maternal depression, symptom load, emotional competences and child behaviour.

The authors declare that they have no conflict of interest.

  partnership separation conflict, to get corrective experiences concerning their view of men and parental resp. couple relationship. Interested kindergarten teachers or other professionals like social workers, therapists are getting to be qualified during a training course of three days for guiding PALME groups. In this training course basic knowledge about leading groups and theoretical knowledge about attachment, developmental psychology and emotional development are taught. The course participants practice individual group sessions on the basis of the manual and exercise moderation techniques practically. Selfawareness exercises focussing on own internalized parental models sensitize the training participants for potentially challenging group situations. The group leaders have a moderating and demonstrating function and serve as a nonnormative model for social learning and conflict management.

  3, only 25% display values ≤ 46.18. The mean value for the physical health is 47.93, values ≤ 42.10 (25. percentile) indicate a bad physical health. The subscale "psychological health" has internal consistency values between .79 and .81 in this investigation.

Figure 1 .Figure 2 .Figure 3 .Figure 4 :Figure 5 :Figure 6 :Figure 7 :Figure 8 :

 12345678 Figure 1. Survey of the study course and the sample recruitment IG = Intervention group, CG = Control group

Table 5 .

 5 Demographic characteristics of intervention group (IG), control group (CG) and Dropouts

	(DO) at t1
	Feature	Specification	IG (N=26) n %	CG (N=35) n %	Test fo IG
	Age	M (SD)	36.6 (5.3)		36.1 (6.0)		F (1/59)
	Native language German	yes no	26 0	100 0	30 5	85.7 Fisher´s 14.3
	Nationality	German not German	26 0	100 0	32 3	91.4 Fisher´s 8.6
	Number of children	M (SD)	1.9 (1.2)		1.7 (0.8)		F (1/59)
	Number of children in preschool age (< 6 years)	M (SD)	0.81 (0.40)		0.97 (0.51)		F(1/59) =
		unmarried	9	34.6	12	34.3
	Family status	separated	11	42.3	8	22.9	χ 2 (df=2)
		divorced	6	23.1	15	42.9
	Established relationship	yes no	6 20	23.1 76.9	8 27	22.9 χ 2 (df=1) 77.1
	School graduation	max. secondary school qualification secondary school certificate	2 9	7.7 34.6	13 13	37.1 37.1	Z=-2.97;
		higher education qualification	15	57.7	9	25.7
		none	2	7.7	8	22.9
	Professional education	traineeship	22	84.6	22	62.9	Z=-0.91;
		technical college/university	2	7.7	4	11.5
	Occupation	yes no	16 10	61.5 38.5	16 19	45.7 χ 2 (df=1) 54.3
	Household net income	Euro, M (SD) total	1555 (458)		1383 (352)		F (1/58)
		Euro, M (SD) each person	606 (201)		546 (133)		F (1/58)
		own income/fortune	13	50.0	13	37.1
	Primary income source	social welfare benefits	6	23.1	19	54.3	χ 2 (df=2)
		alimentation	7	26.9	3	8.6
		never	5	19.2	11	31.4
	Child contact to father	< 1x per month at least 1x / months	3 8	11.5 30.8	8 13	22.9 37.1	Z=-2.37;
		at least 1x / week	10	38.5	3	8.6

Table 6 :

 6 Psychological characteristics of intervention group (IG), control group (CG) and

	Dropouts (DO) at t1
	Measure	Instrument	IG (N=26) M SD	CG (N=35) M SD	Test fo I
	Psychic/psychosomatic strain	SCL-90-R (GSI)	1.01	0.52	0.75	0.53	F (1/56)
	Depression	SCL-90-R (DEP)	1.42	0.79	1.11	0.76	F (1/56)
	Psychological well-being	SF12	35.49	8.65	40.10	9.54	F (1/56)
	Acceptance of own emotions	SEE	19.54	4.88	22.50	4.66	F (1/56)
	Experience of emotional overflow	SEE	21.81	5.32	19.91	6.66	F (1/56)
	Psychogenic impairment	BSS (sum score)	4.46	1.38	4.41	1.91	F (1/49)
	Behavioural problems (children)	SDQ (sum score)	8.33	5.13	7.24	4.60	F (1/26)
	M=mean, SD= standard deviation

Table 7 .

 7 Mean values (MW), standard deviations (SD) and statistical test values (ANOVA) for the psychological variables in the intervention group (IG, N=26) and control group(CG, N=35)

			t1		t2
	Measure		IG M	CG M	IG M	CG M
			(SD)	(SD)	(SD)	(SD)
	Psychic/psychosomatic strain	SCL-90-R, GSI	1.01 (0.52)	0.81 (0.54)	0.52 (0.37)	0.66 (0.45)	F
	Depression	SCL-90-R	1.42 (0.79)	1.17 (0.75)	0.69 (0.58)	0.94 (0.64)	F
	Psychological well-being	SF12	35.49 (8.65)	38.86 (10.12)	45.82 (9.44)	40.80 (10.26)	F
	Acceptance of own emotions	SEE	19.54 (4.88)	22.64 (4.65)	23.23 (3.49)	22.39 (3.98)	F
	Experience of emotional overflow SEE	21.81 (5.32)	20.15 (6.71)	17.35 (4.86)	19.06 (6.65)	F
	Psychogenic impairment	BSS	4.50 (1.33)	4.37 (2.09)	2.23 (1.92)	4.17 (2.55)	F
	Behavioural problems children	SDQ N IG =14; N CG =23	7.12 (5.18)	7.65 (4.96)	5.00 (4.11)	7.57 (6.10)	F

Table 8 .

 8 Results of the intention-to-treat-analysis. Mean values (MW), standard deviations (SD) and statistical test values (ANOVA) for the psychological measures in the original intervention group (IG incl. Dropouts, N=47) and the original control group(CG incl. Dropouts, N=41)

			t1		t2
	Measure		IG M	CG M	IG M	CG M
			(SD)	(SD)	(SD)	(SD)
	Psychic/psychosomatic load	SCL-90-R, GSI	0.94 0.52	0.83 0.54	0.56 0.41	0.71 0.47	F
	Depression	SCL-90-R	1.33 0.71	1.16 0.72	0.78 0.60	0.96 0.63	F
	Psychological well-being	SF12	34.38 8.42	38.69 10.03	44.03 10.11	40.35 10.20	F
	Acceptance of own emotions	SEE N CG =40	20.53 4.66	22.60 4.38	23.26 3.68	22.40 3.80	F
	Experience of emotional overflow	SEE N CG =40	21.02 5.53	20.73 6.52	17.83 5.14	19.83 6.56	F
	Psychogenic impairment	BSS	4.51 1.54	4.37 2.06	3.17 2.26	4.20 2.46	F
	Behavioural problems children	SDQ N IG =25; N CG =27	7.17 5.17	7.95 5.07	5.72 4.41	7.88 6.04	F

PALME = Parental training for Lone Mothers guided by Educators (www.palmeelterntraining.de)

i.e. neurotic spectrum disorders caused and triggered predominantly by psychosocial factors and emotional conflicts like anxiety, depressive, somatoform, or personality disorders, addictions or psychoreactive maladaptation to stressful life events.

Acknowledgements: This study was supported by the Federal Ministry of Education and Research, Germany (BMBF, grant 01EL0411). We thank for the generous funding. Further we appreciate the active support of numerous communal co-workers in the cities Neuss and Hilden. Last but not least we thank the participating mothers and children.

Topic

Central Questions Aims