OBJECTIVE: The authors’ goal was to determine whether treatment of panic attacks has a protective effect on the risk of major depression in the community. METHOD: Data were drawn from the National Comorbidity Survey, a community-based household sample representative of the U.S. adult population. A Cox proportional hazard model was used to estimate the association between risk of first-onset major depression and panic among subjects who had or had not received treatment for panic. RESULTS: A significantly smaller proportion of individuals who received treatment for panic (19%) than those who did not receive treatment (45%) developed major depression. This difference remained significant in a Cox proportional hazard analysis adjusted for age at onset of panic and differences in demographic characteristics. CONCLUSIONS: Detection and treatment of panic may reduce the risk of developing major depression.