Rapid Antidepressant Response with Ketamine: Is it the Solution to Resistant Depression?

BACKGROUND: Treatment-resistant depression (TRD) is a relatively common condition, challenging the clinician. There is an urgent need to develop pharmacological treatments for TRD that exert rapid and sustained antidepressant effects. Ketamine induces a rapid antidepressant effect. AIMS: In India, very few studies have corroborated such findings, and the present study aimed to assess the effectiveness and sustainability of antidepressant effects of ketamine in subjects with TRD. MATERIALS AND METHODS: The present study was a single-center, prospective, 4-week, open-label, single-arm pilot study. Twenty-two subjects with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition major depression (treatment resistant) were recruited. After a 2-week drug-free period, subjects were given a single intravenous infusion of ketamine hydrochloride (0.5 mg/kg) and were rated at baseline and at 40, 80, 110, and 230 min and 1, 2, 3, 4, 7, and 14 days postinfusion. The main outcome measure was changes in scores on the 17-item Hamilton Depression Rating Scale (HDRS). Data were analyzed by using Freidman's analysis of variance and a post hoc test. RESULTS: The ketamine infusion was effective in reducing the HDRS scores, and the change remained significant from minute 80 to day 3 postinfusion at each time point. The change was not significant at any time after day 3. CONCLUSION: The real strength of this study rests in documenting the rapid, albeit short-lived, antidepressant effect of ketamine in TRD.