Anxiety disorders: similarities and differences of comorbidity in treated and untreated groups.

The similarities and differences of comorbidity in treated and untreated samples with anxiety disorders were examined using data from the Munich Follow-up Study: 133 subjects with anxiety and depressive disorders and 101 former in-patients at the Max Planck Institute for Psychiatry. Diagnoses were based on the DIS, not using the optional DSM-III exclusion rules. In these epidemiological and clinical samples, 69% and 95% respectively had at least two diagnoses. The epidemiological sample was clearly differentiated from the clinical sample by age of onset. The development of both depressive episodes and substance disorders in the two samples was mostly secondary to the development of anxiety problems. The outcome for subjects with both anxiety and depressive disorders tended to be worse than that for those with anxiety alone, regardless of whether a depressive episode was present at the time of the follow-up investigation. The usefulness is underlined of the comorbidity concept based on operationalised diagnosis without the exclusion rules offered by DSM-III and DSM-III-R.