Does social support affect the relationship between socioeconomic status and depression? A longitudinal study from adolescence to adulthood

Background: The aim of this prospective longitudinal study of adolescents was to investigate socioeconomic differences in adult depression and in the domain of social support from adolescence to adulthood. We also studied the modifying effect of social support on the relationship between socioeconomic status (SES) and depression. Methods: All 16-year-old ninth-grade school pupils of one Finnish city completed questionnaires at school (n=2194). Subjects were followed up using postal questionnaires when aged 22 and 32 years. Results: At 32 years of age there was a social gradient in depression, with a substantially higher prevalence among subjects with lower SES. Low parental SES during adolescence did not affect the risk of depression at 32 years of age, but the person's lower level of education at 22 years did. Lower level of support among subjects with lower SES was found particularly in females. Some evidence indicated that low level of social support had a greater impact on depression among lower SES group subjects. However, this relationship varied depending on the domain of social support, life stage and gender. On the other hand, the results did not support the hypothesis that social support would substantially account for the variation in depression across SES groups. Limitations: The assessments and classifications of social support were rather brief and crude, particularly in adolescence and early adulthood. Conclusions: It is important to pay attention to social support resources in preventive programs and also in the treatment settings, with a special focus on lower SES group persons. (C) 2006 Elsevier B.V. All rights reserved.