A search of all multiple admissions to the University of Iowa Psychiatric Hospital yielded 20 bipolar patients first admitted during adolescence and 21 bipolar patients first admitted between the ages of 30 and 40 years. Inclusion required the patient to meet criteria for mania on some admission other than the first. Adolescents were as likely as adults to meet criteria for mania and/or depression during their first admission. There were no group differences in distribution of criteria symptoms or in rates of associated symptoms. Likewise, the groups had similar rates of recovery at discharge and subsequent time spent in hospital. The authors conclude that differences between adolescents and adults need not obscure an appropriate diagnosis of mania.