This article discusses how psychosocial health in adolescence influences adult mental health among former students with special educational needs in Norway. These individuals have been followed prospectively from their teens and into their mid-30s. The study is inspired by life course perspectives with an emphasis on cumulative processes. The logistic regression analysis reveals that the risk of suffering from adult mental distress is higher among those with psychosocial difficulties in their juvenile years compared with those without such problems. Our results also show that the mental health of subjects who experienced health problems and received social security benefits in their late 20s is negatively affected when they are 33 to 34 years of age. In addition, the risk of poor adult mental health is considerably higher for females than males. Receiving assistance from teaching assistants in the classroom at upper secondary school does not seem to be conducive to subsequent positive mental health.