Systematic review of the outcome of anxiety and depressive disorders

BACKGROUND: Although there have been many changes in the diagnosis of anxiety and depressive disorders in the past 20 years there have been few comparative enquiries into the clinical outcome of greater diagnostic categories. We therefore compared the outcome of all studies which compared the outcome of specific anxiety and depressive disorders using the standard procedures of systematic review. METHOD: A Medline search was carried out of all studies comparing the outcome of anxiety and depressive disorders or mixed anxiety--depressive disorders in which information was available separately for each disorder. RESULTS: Eight studies satisfied the search criteria (all involving a period of observation of two years or greater); only one of these included randomisation of treatment and comparison between specific anxiety disorder outcome. There was a somewhat better outcome in patients with depressive disorders compared with anxiety ones, and strong evidence that both anxiety and depressive disorders singly had better outcomes than comorbid mixed disorders. CONCLUSION: Comorbid anxiety--depressive disorders have a poor outcome compared with single anxiety and depressive disorders, and there is some evidence that anxiety disorders have a worse outcome than depressive ones.