Developmental relationships between socio-economic disadvantage and mental health across the first 30 years of life

Understanding of how socio-economic disadvantage experienced over the life course relates to mental health outcomes in young adulthood has been limited by a lack of long-term, prospective studies. Here we address this limitation by drawing on data from a large Australian population cohort study that has followed the development of more than 2,000 Australians (and their families) from infancy to young adulthood since 1983. Associations were examined between prospective assessments of socio-economic position (SEP) from 4–8 months to 27–28 years and mental health problems (depression, anxiety, stress) and competence (civic engagement, emotional maturity, secure intimate relationship) at 27–28 years. The odds of being socio-economically disadvantaged in young adulthood were elevated eight-to tenfold in those who had experienced disadvantage in the family of origin, compared with those who had not (OR 8.1, 95% CI 4.5–14.5 to 10.1, 95% CI 5.2–19.5). Only concurrent SEP was associated with young adult mental health problems, and this effect was limited to anxiety symptoms (OR 2.0, 95% CI 1.1–3.9). In contrast, SEP had more pervasive impacts on young adult competence, particularly in the civic domain where effects were evident even from early infancy (OR 0.46, 95% CI 0.26–0.81). Findings suggest that one potentially important mechanism through which disadvantage compromises mental health is through limiting the development and consolidation of key psychosocial competencies needed for health and well-being in adulthood.