Data from the National Institute of Mental Health (NIMH) Epidemiologic
Catchment Area Program, an epidemiologic survey of five communities, showed
that four major disorders commonly begin in late adolescence or young
adulthood. The median age at onset for anxiety disorders is 15 years; for
major depressive episode, 24 years; for drug abuse or dependence, 19 years;
and for alcohol abuse or dependence, 21 years. Findings also suggest that
for respondents 18-30 years old, having a major depressive episode or
anxiety disorder doubles the risk for later drug abuse or dependence.