Avoidance behaviour and major depression in panic disorder: a report from the Cross-National Collaborative Panic Study.

Avoidance behaviour and secondary major depression are both frequent in clinical samples of patients with panic disorder. Their status is unclear: indicators of severity of panic disorder or indicators of separate psychiatric disorders. Among the data of the Cross-National Collaborative Panic Study (n = 1,168) we found that especially avoidance behaviour defines more severe states of panic disorder (earlier age at onset, higher frequency of panic attacks and higher level of psychopathology); co-occurrence of major depression is less clearly associated with more severe panic disorder. The results are compatible with the DSM-III-R concepts of comorbidity of panic disorder and major depression and of subtyping panic disorder by avoidance behaviour.