Park LT, Luckenbaugh DA, Pennybaker SJ, et al. - Researchers examined if and how a single intravenous dose of ketamine affects general depressive symptoms (assessed via the Montgomery–Asberg Depression Rating Scale, typical/melancholic symptoms (measured using the, and atypical symptoms (measured using the Scale for Atypical Symptoms). From three different, double‐blind, placebo‐controlled, crossover studies evaluating if ketamine is effective in depression, data were retrieved on 68 participants with treatment‐resistant major depressive disorder (MDD) or bipolar depression. MDD patients were not on medication; bipolar patients were provided therapeutic‐dose lithium or valproate. Outcomes suggest ketamine was effective in treating both typical/melancholic and atypical symptoms of depression, but effect sizes were larger for typical/melancholic on Day 1 .