Chronic depression: response to placebo, imipramine, and phenelzine.

We reanalyzed data from a larger, previously published study in order to directly address whether very chronically depressed patients could benefit from antidepressant medications. This study entered 598 depressed patients into a study randomizing patients to 6 weeks of double-blind treatment with imipramine, phenelzine, or placebo. Patients were assessed for chronicity on a four-point scale from "mostly well" to "virtually always depressed." The current analyses include only the 153 study completers who were rated as "virtually always depressed." In these patients, imipramine was effective for significantly more patients than was placebo (22 [46%] of 48 responding to imipramine vs. 9 [17%] of 52 responding to placebo; chi 2 = 9.50; p = 0.002), whereas phenelzine was significantly more effective than imipramine (37 [70%] of 53 responding to phenelzine; chi 2 = 5.96; p = .015). Patients with mild depression, early onset, or histories of panic attacks did not have substantially different outcomes than patients without these characteristics. These findings suggest that some chronically depressed patients may be good candidates for treatment with antidepressant medication. Because the majority (80%) of the sample met Columbia criteria for definite or probable atypical depression, too few chronic depressives were available to evaluate separately antidepressant efficacy in chronically depressed outpatients who did not have atypical depression. Hence, these results may be applicable only to patients with atypical depression.