Background. Our objective was to estimate the lifetime prevalence of psychopathology in a sample of youth with and without attention deficit hyperactivity disorder (ADHD) through young adulthood using contemporaneous diagnostic and analytic techniques.

Method. We conducted a case-control, 10-year prospective study of ADHD youth. At baseline, we assessed consecutively referred male, Caucasian children with (n=140) and without (n=120) DSM-III-R ADHD, aged 6–18 years, ascertained from psychiatric and pediatric sources to allow for generalizability of results. At the 10-year follow-up, 112 (80%) and 105 (88%) of the ADHD and control children, respectively, were reassessed (mean age 22 years). We created the following categories of psychiatric disorders: Major Psychopathology (mood disorders and psychosis), Anxiety Disorders, Antisocial Disorders (conduct, oppositional-defiant, and antisocial personality disorder), Developmental Disorders (elimination, language, and tics disorder), and Substance Dependence Disorders (alcohol, drug, and nicotine dependence), as measured by blinded structured diagnostic interview.

Results. The lifetime prevalence for all categories of psychopathology were significantly greater in ADHD young adults compared to controls, with hazard ratios and 95% confidence intervals of 6·1 (3·5–10·7), 2·2 (1·5–3·2), 5·9 (3·9–8·8), 2·5 (1·7–3·6), and 2·0 (1·3–3·0), respectively, for the categories described above.

Conclusions. By their young adult years, ADHD youth were at high risk for a wide range of adverse psychiatric outcomes including markedly elevated rates of antisocial, addictive, mood and anxiety disorders. These prospective findings provide further evidence for the high morbidity associated with ADHD across the life-cycle and stress the importance of early recognition of this disorder for prevention and intervention strategies.