Background: The effectiveness of monoamine oxidase inhibitors (MAOIs) in tricyclic resistant depression has received surprisingly little systematic study.
Method: Patients who failed to respond to sustained, adequate treatment with the tricyclic imipramine (mean maximum dosage = 260 mg/day) and interpersonal psychotherapy were withdrawn from imipramine and treated in a standardized, but open-label 6-week trial with either phenelzine (N = 4; 60 mg/day) or tranylcypromine (N = 36; mean = 38.5 mg/day) and continued interpersonal psychotherapy.
Results: Forty of 42 patients (95%) completed the trial, of whom 23 (58%) responded to treatment. Highly significant improvement was documented on measures of depression, reversed neurovegetative symptoms, and somatic symptoms. Response was significantly correlated with severity of depression (pre-MAOI score on the Hamilton Rating Scale for Depression), severity of a composite score of anergic and reversed neurovegetative features, and low levels of improvement during initial imipramine/interpersonal psychotherapy. Of patients who met criteria for proposed subforms of anergic or atypical depression, 67% (18/27) responded (p less than .05); 77% (17/22) of patients who scored above the mean on the composite measure of anergic and reversed neurovegetative features responded (p less than .01).
Conclusion: These findings provide strong evidence of the utility of MAOIs in tricyclic-resistant depression, especially in patients with features such as fatigue, volitional inhibition, motoric retardation, hypersomnia, and/or weight gain.