Does problem behaviour affect attrition from a cohort study on adolescent mental health?

BACKGROUND: Most surveys are plagued by significant numbers of non-respondents. In psychiatric epidemiology, differences in levels of psychopathology are often assumed between respondents and non-respondents. However, studies on attrition are rare, especially in child and adolescent populations. The present study sought to estimate the association of depression, anti-social behaviour with attrition from a cohort study among adolescents. METHODS: The adolescent mental health cohort study (AMHC) is a prospective follow-up study on prevalence and determinants of mental health problems and risk behaviour among Finnish adolescents at two study sites. Subjects of the final baseline sample (n = 3278) were reached for a 2-year follow-up. Differences in data collecting methods between the study sites yielded different response rates (78% vs. 51%). Chi-square statistics and logistic regression models were computed to estimate the effect of two types of problem behaviour on attrition. RESULTS: Depression at baseline was associated with higher probability of attrition at follow-up. School performance was a stronger predictor of attrition than problem behaviour. The models predicted non-response in the study site with mainly school-based surveys but not in the study site with mainly postal surveys. CONCLUSION: Internalizing problem behaviour may be underrepresented in adolescent mental health surveys. School performance is strongly associated with attrition. Hence, special attention should be paid to designing questionnaires targeting adolescents.

Depression and school performance in middle adolescent boys and girls.

The study aimed to investigate the associations between different levels of depression with different aspects of school performance. The target population included 2516 7th-9th grade pupils (13-17 years) of whom 90% completed the questionnaire anonymously in the classroom. Of the girls 18.4% and of the boys 11.1% were classified as being depressed (R-Beck Depression Inventory (BDI), the Finnish version of the 13-item BDI). The lower the self-reported grade point average (GPA) or the more the GPA had declined from the previous term, the more commonly the adolescents were depressed. Depression was associated with difficulties in concentration, social relationships, self-reliant school performance and reading and writing as well as perceiving schoolwork as highly loading. The school performance variables had similar associations with depression among both sexes when a wide range of depression was studied but gender differences appeared when studying the severe end of the depression scale. Our study indicates that pupils reporting difficulties in academic performance should be screened for depression.