Background: Previous studies have reported the efficacy of selective serotonin reuptake inhibitors as monotherapy in the treatment of delusional depression. The clinical efficacy of venlafaxine, a serotonin-norepinephrine reuptake blocker, has been demonstrated in the treatment of patients with moderate-to-severe depression, but, to date, no evidence is available about its use in depressed patients with psychotic features.

Method: Under double-blind conditions, 28 hospitalized patients who met DSM-IV criteria for major depression, severe with psychotic features, were randomly assigned to receive fluvoxamine or venlafaxine, 300 mg/day, for 6 weeks. Severity was evaluated using the Hamilton Rating Scale for Depression (HAM-D) and the Dimensions of Delusional Experience Rating Scale (DDERS) administered at baseline and every week thereafter. Side effects were also recorded. Clinical response was defined as a reduction of the scores in the 21-item HAM-D to 8 or below and in the DDERS to 0.

Results: At study completion, the response rates were 78.6% (N = 11) and 58.3% (N = 7) for fluvoxamine and venlafaxine, respectively. No significant difference was found between drugs (Fisher exact test, p = .40). Analysis of covariance on HAM-D scores did not reveal a significantly different decrease of depressive symptomatology between the 2 treatment groups (p = .14). Treatment response appeared to be unrelated to the demographic and clinical characteristics recorded. The overall safety profile of both fluvoxamine and venlafaxine was favorable.

Conclusion: The results of this pilot double-blind trial show that fluvoxamine is useful in the treatment of delusional depression and suggest that venlafaxine may also be an effective compound in the treatment of this disorder. The latter finding, although promising, warrants further replication in a larger sample of patients.