Davis MT, DellaGiogia N, Maruff P, et al. - Since intravenous (IV) subanesthetic doses of ketamine have been shown to decrease psychiatric distress in both major depressive (MDD) and posttraumatic stress disorder (PTSD), researchers sought to investigate the influence of a single dose of IV ketamine on cognition in people with MDD and/or PTSD compared to healthy controls (HC). The community was used to recruit psychiatric (n = 29; 15 PTSD, 14 MDD) and sex- age- and IQ matched HC (n = 29) groups. A single subanesthetic IV ketamine dose was administered. Cognitive function (baseline, change from baseline to post-ketamine) was not related to ketamine's antidepressant response. While ketamine may have an acutely negative effect on some cognitive domains in both MDD/PTSD and HC individuals, most notably attention, the results suggest that this effect is transient, and there is no evidence of ketamine-related cognitive dysfunction at 1-day post-administration.