Further evidence for a developmental subtype of bipolar disorder defined by age at onset: Results from the national epidemiologic survey on alcohol and related conditions

Objective: This study examines the relationship between age at onset of bipolar I disorder and illness characteristics among adults in a community sample. Method: The National Epidemiologic Survey on Alcohol and Related Conditions identified 1,411 adults with bipolar disorder. For analyses, bipolar disorder subjects were divided into three age at onset groups: childhood (less than 13 years old, N = 113), adolescence (13 - 18 years old, N = 339), and adulthood (19 years or older, N = 959). Results: Nonremitting bipolar disorder was most prevalent among childhood-onset subjects, and childhood- onset subjects were most likely to experience prolonged episodes. Antisocial personality disorder was most prevalent among childhood-onset subjects. Drug use disorders were more prevalent among childhood- onset and adolescent-onset, as compared with adult-onset, subjects. Prevalence of mixed episodes or irritability did not differ significantly between groups. Conclusions: Findings corroborate clinical studies: illness characteristics among adults with childhood-onset bipolar disorder are similar those described in children with bipolar disorder.