Background: The co-occurrence of panic disorder and major depression in the same individual is common. A question to be answered is whether the comorbid disorder is a distinct one or may resemble one or other disorder. In this paper we examine whether the comorbid disorder is a distinct condition.
Method: We examined the symptom profiles and rates of comorbidity of panic attacks and DIS/DSM-III major depressive disorder in a population-based sample from four sites of the National Institute of Mental Health (NIMH) Epidemiologic Catchment Area Program (n = 12,668).
Results: The co-occurrence of panic attacks and major depression over the lifetime was 11 times higher than expected by chance (OR = 11.4, 95% CI 9.5 to 13.6). Subjects with both panic and depression had worse symptoms than those who had only one disorder. However, the pattern of symptoms was remarkably similar, after overall severity was taken into account. Depressive symptoms associated with more severe forms of depression (e.g. guilt, suicidal thoughts or attempts, and motor disturbance) were more frequent in the comorbid group.
Conclusions: These findings may indicate a worse severity when the two disorders occur in the same individual.