BACKGROUND: Controversy surrounds the frequency of underdiagnosis vs overdiagnosis of bipolar disorder (BD) in children and adolescents compared with diagnoses of attention-deficit/hyperactivity disorder (ADHD) and major depressive disorder (MDD).

METHODS: Sixty-four children and adolescents (age 7 to 18) treated in a community setting were systematically assessed for diagnostic and treatment histories. Best estimate consensus diagnosis was made using DSMIV criteria.

RESULTS: ADHD was overdiagnosed (all patients with ADHD had received the diagnosis, as did 38% of patients with MDD and 29% of patients with BD, respectively), while MDD was partially underdiagnosed and partially overdiagnosed (57% of MDD patients received the diagnosis, 43% did not; 33% of patients with BD were incorrectly diagnosed with MDD). BD was underdiagnosed, not overdiagnosed (38% received the diagnosis, 62% did not; BD was not diagnosed in the ADHD sample, and in only 5% of the patients with MDD). The absence of a positive family history predicted misdiagnosis of BD (relative risk = 2.48, 95% confidence interval 1.10 to 5.56). Observational treatment response to stimulants was equally high in all groups (75% to 82%).

CONCLUSIONS: In the first controlled study on this topic, BD was not overdiagnosed in children and adolescents, as it is often claimed, and ADHD was. Stimulant response was nonspecific and diagnostically uninformative. Studies with larger samples are needed to replicate or refute these results.