Context: The relationship between comorbid panic and suicide in depressed persons remains unclear. Objective: To examine the relationship of panic attacks and panic symptoms to suicidality in individuals with a major mood disorder meeting DSM-IV criteria for past-year major depressive episodes in a large epidemiologic study. Method: In data on 2,679 community-dwelling participants of the National Epidemiologic Survey on Alcohol and Related Conditions (2001-2002) with major depressive episodes, the associations of panic attacks and panic symptoms with lifetime suicidal ideation and suicide attempts were assessed. The adjusted odds ratios (AORs) of suicidal ideation, suicide attempt, and suicide attempt among ideators for subjects with panic attacks were the primary outcome measures. Results: Past-year panic attacks were associated with increased risk of lifetime suicidal ideations (AOR = 1.17; 95% CI, 1.02-1.35) and suicide attempts (AOR = 2.10; 95% CI, 1.77-2.50) and significantly increased risk of suicide attempts among those reporting suicidal ideations (AOR = 1.79; 95% CI, 1.49-2.15). Some panic symptoms, most notably catastrophic cognitions (fear of dying and fear of "losing control" or "going insane"), were more strongly and specifically associated with suicide attempt (AORs = 2.13-2.95), while others were more related to suicidal ideation. Conclusions: Panic attacks appear to be an independent risk factor for suicide attempt among depressed individuals with and without suicidal ideation. Further, panic attacks, particularly those characterized by prominent catastrophic cognitions, may mediate the transition from suicidal ideations to suicide attempts in subjects with depressive episodes. Assessment of these symptoms may improve prediction of suicide attempts in clinical settings.