Prospective studies of cothymia (mixed anxiety-depression): how do they inform clinical practice?

We suggest that the diagnosis of mixed anxiety depression at syndromal level (i.e. both anxiety and depressive diagnoses present in the same person and given equal status) is valuable clinically and should be introduced into the formal classification of neurotic and mood disorders. Evidence is given from a systematic review that cothymia has a significantly worse outcome than either an anxiety or a depressive diagnosis alone (p < 0.0001). Long-term follow-up data in a 12-year outcome study of neurotic disorder reinforce this finding both with regard to social functioning and the clinical course of anxiety and depressive disorders; these were significantly worse (P < 0.001 and P < 0.02 respectively) in those with cothymia compared with single anxiety disorders. These outcome differences are much greater than those between anxiety and depressive disorders alone.