The objective of this study was to replicate previous findings indicating that early-onset panic attack (≦20 years) with fear represents a possible prodrome of early-onset severe psychopathology. Data were drawn from the Epidemiologic Catchment Area Survey (ECA) (n=20 291), a household sample of adults aged 18 and older drawn from five cities in the United States. Multivariate logistic regression analyses were used to differentiate those with early-onset panic attacks with fear from those with other panic attacks (early-onset without fear, late-onset without fear, late-onset with fear) with regard to psychiatric comorbidity, age at onset of comorbid mental disorders, and suicidal ideation and suicide attempts. Results of statistical analyses revealed that early-onset fearful panic attack (n=368) was associated with increased likelihood of major affective and substance use disorders, significantly earlier onset of comorbid mental disorders, higher rates of suicidal ideation and suicide attempt, and higher rates of antisocial personality disorder compared with those with other subtypes of panic attacks. Multiple logistic regression analyses showed that early-onset fearful panic was independently associated with increased odds of major depression [OR=3.0 (2.6, 3.5)], bipolar disorder [OR=7.9 (5.7, 10.8)], antisocial personality disorder [OR=1.5 (1.3, 1.7)], agoraphobia [OR=1.2 (1.1, 1.4)], simple phobia [OR=1.6 (1.4, 1.8)], and alcohol dependence [OR=1.3 (1.2, 1.5)], compared with those with all other panic attacks. These findings are consistent with previous epidemiologic data and provide new evidence to suggest that early-onset fearful panic attack may be a marker of increased vulnerability to severe and persistent psychopathology and associated with high rates of suicidality. [Copyright &y& Elsevier]