Wang C, Zhou Y, Zheng W, et al. - Researchers examined how depression subtypes influence response to ketamine. They administered six repeated-dose intravenous ketamine to 97 participants with depression and assessed them for depression (Montgomery-Åsberg Depression Rating Scale, MADRS), anxiety (Hamilton Anxiety Rating Scale, HAMA), and suicidal ideation (Beck Scale for Suicidal Ideation, SSI) at baseline, 24 hours after each infusion, and 2 weeks after the whole treatment. Among patients with melancholic or melancholic-anxious features, less tendency to respond (eg, day 13, melancholic-anxious vs anxious, OR 0.138, 95% CI 0.032–0.584, P = 0.007) or remit (eg, day 26, melancholic vs. no subtype, OR 0.182, 95% CI 0.035–0.960, P = 0.045) was observed; further these cases took longer time to achieve response/remission than those with anxious or no subtype features. Patients with anxious or melancholic-anxious features had faster HAMA score reductions, and those with melancholic-anxious features had faster SSI score reductions. Promising results supporting ketamine as a novel antidepressant, preferentially for treating non-melancholic or anxious depression, were thus reported in this work.