In this study, the association and outcome of panic and depression were investigated in an epidemiological cohort of young adults interviewed at age 21, 23, and 28. The prevalence rates of sporadic panic, panic disorder, major depression, and recurrent brief depression were very stable. There was a clear preponderance of females in all diagnoses. Panic and depression overlapped to a large extent cross-sectionally at all 3 interviews, and this overlap increased in a longitudinal perspective. For the analysis of outcome, the subjects were divided into 4 groups according to their diagnosis at the first interview: pure panic, pure depression, mixed panic and depression, and controls. Irrespective of the first diagnosis, the 7-year outcome showed a strong tendency to develop into pure depression or mixed panic and depression at follow-up interviews. In a longitudinal perspective, cases that suffered from both panic and depression appeared more severely ill, as expressed in very high treatment rates and a high rate of lifetime suicide attempts.