Determinants of Depressive Symptoms in Adolescents The Role of Sexual Harassment and Implications for Preventive Interventions

Abstract: Background: Depression is considered the worldwide leading cause of illness and disability in young people and an urgent public health issue. Within the field of public health it is of interest to deepen the understanding of determinants of depressive symptoms (DS) that are possible to address on a political or an organizational level. Also, it is of great importance to find methods to prevent depression in adolescents. To address these issues, the present thesis had two Aims: I) To study determinants of DS in adolescents, and II) to, by means of a non-randomized pragmatic trial evaluation, investigate the effectiveness a cognitive-behavioral intervention (DISA) in a real-world setting in relation to determinants of DS in adolescent girls. This was addressed by asking a) Which determinants on individual, psychosocial and structural levels are associated with DS in adolescents? (Paper I); b) What are the directional pathways between sexual harassment (SH) and DS? (Paper II); c) Which features characterize students who were assigned to a cognitive-behavioral intervention regarding levels of DS, psychosocial aspects and socioeconomic status of the respondents as well as of schools? (Paper III); d) Does DISA have an effect on DS in girls aged 14-16? (Paper IV); and e) Are there differences between the DISA participants and non-participants in the effects of psychosocial and structural determinants on DS? (Paper IV). Method: Data was collected in January 2010, 2011, and 2012, by means of a self-administered, electronic questionnaire in school. Students aged 14-16 in all nine public and one independent high school in a municipality in northern Sweden participated in the study (~1,000-1,200 students depending on the wave). All studies had DS as the single outcome variable. Individual level determinants were self-esteem and self-efficacy. Psychosocial determinants were parental/peer/teacher support; school demands; sexual harassment; and bullying. Structural determinants were family material affluence; parental foreign background, parental employment status; disrupted family, and personal relative affluence. Logistic regression was employed for research question a) (Paper I). Structural equation (SEM) cross-lag models were modeled for research question b) (Paper II). The Mann-Whitney U statistic was employed for research question c) (Paper III). SEM was used for research questions d-e) (Paper IV). Results: Determinants on individual, psychosocial and structural levels were independently associated with depressive symptoms in both genders. Self-efficacy, low teacher support, bullying victimization, and low personal relative affluence was associated with elevated levels of DS in both genders (Paper I). In girls, low parental support, high school demands, and sexual harassment victimization (SH) were also associated with elevated levels of DS. Among boys, parental migrant background was also associated with DS. Among girls, both the targeting of girls with elevated DS, and the consequence of SH explained the relationship between DS and SH victimization over time. In boys, only the predating of DS explained the association between DS and SH (Paper II). Only girls were assigned to DISA during 2011 and DISA participants reported higher levels of DS and lower levels of self-esteem than the non-participants at pre-intervention, which indicates that DISA was used as a targeted intervention for girls with elevated symptoms. Also, DISA participants reported higher levels of SH victimization, less peer support, and lower personal relative affluence (Paper III). In contrast to the non-participants, DISA participants did not increase their mean scoring on DS at an eight months follow-up. However, SEM analyses showed that the effect of DISA participation on DS at follow-up was negligible (Paper IV). Conclusions: This study showed that SH victimization was an important determinant for DS in girls followed by personal relative affluence. Among boys, personal relative affluence and parental migrant background were the most important factors. SH victimization had mental health consequences in girls only. DISA was implemented as a targeted intervention rather than as selective or universal one, and did not have an effect on DS in this group of girls. Implications for further research and health promotion practice in the school setting are discussed.