Comorbidity of anxiety disorders and depression: does it affect course and outcome?

Abstract

SummaryThe comorbidity of anxiety disorders and depression, and its effect on course and outcome was examined by using data from the Munich Follow-up Study (MFS). The MFS is a prospective 7 year follow-up study in both a clinical sample of originally 291 former inpatients as well as a representative sample (N = 657) from the general population. Diagnoses were based on the Diagnostic Interview Schedule (DIS) not using the optional DSM-III exclusion rules. Based on earlier studies the temporal relationship of diagnoses was examined by using the age of onset and recency codings of the DIS, correcting for inaccuracies in patients’ judgement. The results showed: 1), Comorbidity seems to be a rather frequent and stable phenomenon in clinical and epidemiological samples. The comorbidity rates of the DIS/DSM-III diagnoses, amounted to about 50% in the epidemiological and 75% in the clinical sample. 2), The majority of the subjects with both disorders indicated an onset of anxiety disorders before that of a major depressive syndrome. None of the cases developed a major depressive episode prior to an anxiety disorder. 3), A less favorable course and outcome was generally found for subjects with both disorders (anxiety and depression), although the predictive value of the diagnostic grouping was meager. Clear differences were found for “pure” disorders (anxiety only, depression only) in the clinical and epidemiological sample. 4), Regardless of whether a depressive episode was present at the time of the follow-up investigation, the mixed group had the worst outcome of all other comparative groups.