Background: Adolescents' mental health is a major public health issue. Previous research has shown that socio-economic factors contribute to the health status of adolescents. The present study explores the association between socio-economic status and self-rated mental health among adolescents.

Methods: Cross sectional data from the Halmstad Youth Quality of Life cohort was collected in a town in Sweden. In all, 948 adolescents (11-13 younger age group and 14-16 older age group) participated. Information on self-rated mental health was collected from the subscale Psychological functioning in the Minneapolis Manchester Quality of Life instrument. The items were summarized into a total score and dichotomized by the mean. Indicators measuring socio-economic status (SES) were collected in a questionnaire using the Family Affluence Scale (FAS) and additional factors regarding parents' marital status and migration were added. Logistic models were used to analyze the data.

Results: Girls were more likely to rate their mental health below the mean compared to boys. With regard to FAS (high, medium, low), there was a significantly increased risk of self-rated mental health below the mean among younger boys in the medium FAS score OR; 2.68 (95% CI 1.35;5.33) and among older boys in the low FAS score OR; 2.37 (1.02;5.52) compared to boys in the high FAS score. No such trend was seen among girls. For younger girls there was a significant protective association between having parents born abroad and self-rated mental health below mean OR: 0.47 (0.24;0.91).

Conclusions: A complex pattern of associations between SES and self-rated mental health, divergent between age and gender groups, was shown. The total FAS score was only associated with boys' self-rated mental health in both age groups, whereas parents' migratory status influenced only the girls' self-rated mental health. Because of the different association for girls' and boys' self-rated mental health and SES, other factors than SES should also be considered when investigating and exploring the mental health of adolescents in affluent communities. © 2014 Hutton et al.; licensee BioMed Central Ltd.