Objective: One of the proposed revisions for DSM-5 is to rate panic attacks as a separate dimension across all mental disorders. The idea is that panic attacks occurring outside panic disorder are a dimension predicting important clinical outcomes. The aim of this study was to validate the proposition for DSM-5 that panic attacks have predictive value for overall psychopathology onset, course, and functioning. Method: Data were derived from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a prospective population-based study. Using the Composite International Diagnostic Interview (with classifications based on DSM-III-R), 5,571 subjects were selected who had (1) no panic history, (2) a history of panic attacks (but no panic disorder), (3) current panic attacks, or (4) current panic disorder. The impact of panic status on the prevalence of anxiety, affective, alcohol, and any mental disorders; on the onset and persistence of these disorders during 3-year follow-up; and on levels of functioning during 3-year follow-up (as assessed with the 36-Item Short-Form Health Survey) was examined. Results: Current panic attacks outside the realm of panic disorder were associated with increased prevalence of mental disorders (?2<inf>3</inf> = 490.6; P < .001), increased onset of mental disorders (hazard ratio = 4.42; 95% CI, 2.88-6.80), persistence of mental disorders (odds ratio = 2.72; 95% CI, 1.53-4.82), and impaired functioning during 3-year follow-up (F = 69.67; P < .001). Although the impact was smaller than for panic disorder, the associations identified for panic attacks were consistent and significant and were, to a lesser extent, also found for a history of panic attacks. Conclusions: Given the consistent impact of panic attacks on various aspects of psychopathology, the proposition to dimensionally rate panic attacks across all mental disorders may be of great value for clinical care. © Copyright 2012 Physicians Postgraduate Press, Inc.