Depression Severity with Ketamine Treatment in Clinical Procedures

Abstract

Ketamine has developed as a rapid-acting antidepressant in treatment-resistant depression increasingly used in non-research, clinical settings. Few studies, have scrutinized neurocognitive activities of repeated racemic ketamine infusion treatments in patients with treatment-resistant depression. In an effort to identify potential effects after serial infusions, we conducted a retrospective chart review to identify statistically significant changes in cognition in patient undergoing serial intravenous infusions; concomitantly, we examined baseline cognition as potential predictor of anti-depressant potential. Twenty-two patients with treatment-resistant depression were examined after they finished the induction phase of 8–10 repeated intravenous ketamine infusions and completed the assessments of their depressive symptoms (measured by the 16-item Quick Inventory of Depressive Symptomatology-Self Report Scale: QIDS-SR16) and cognitive function (measured by the Montreal Cognitive Assessment: MoCA) before the first and the last ketamine treatments. Repeated ketamine infusions administered through an escalating dose protocol with 8–10 infusion sessions produced a 47.2% reduction response in depression. Ketamine was approved under a risk evaluation and mitigation strategy (REMS) that requires administration under medical supervision. Both ketamine and ketamine are currently viable treatment options for TRD that offer the possibility of rapid symptom improvement. The manuscript also reviews ketamine’s use in other psychiatric diagnoses—including suicidality, obsessive–compulsive disorder, post-traumatic stress disorder, substance abuse, and social anxiety disorder—and its potential adverse effects. Despite limited data, side effects for antidepressant-dose ketamine—including dissociative symptoms, hypertension, and confusion/ agitation—appear to be tolerable and limited to around the time of treatment. Relatively little is known about ketamine’s longer-term effects, including increased risks of abuse and/or dependence. Attempts to prolong ketamine’s effects with combined therapy or a repeat-dose strategy are also reviewed, as are current guidelines for its clinical use. In addition to presenting a novel and valuable treatment option, studying ketamine also has the potential to transform our understanding of the mechanisms underlying mood disorders and the development of novel therapeutics.