Mental health disorders from age 15 to age 18 years.

OBJECTIVE: To determine the strength of association between mental health disorders in adolescence and disorder in early adulthood.
METHOD: The study used mental health data from a longitudinal investigation of a New Zealand birth cohort. Of the 943 with prevalence data for DSM-III disorder at age 15, 890 had prevalence data for DSM-III-R disorder when aged 18 years.
RESULTS: Two-thirds of those with disorder at age 15 had disorder at age 18. The residual form of attention deficit disorder, simple phobias, and oppositional disorders (with no other accompanying disorders) were associated with the lowest risk of later disorder and conduct disorder with the highest. With the exception of the overall symptom level, a variety of characteristics examined (e.g., social competence and adversity) could not differentiate between those with transient disorder and those with disorder at both ages. Comparisons of those with recurring disorder and those with new disorder at age 18 showed that in addition to characteristics of the disorder, disadvantage was strongly associated with recurrent disorder.
CONCLUSIONS: The risk of later disorder for those with disorder in adolescence was high and differed across type of disorder. Findings suggest that to reduce the risk of disorder in early adulthood, clinicians could play a more active role in community interventions with direct social outcomes.