(Es)ketamine in functional neurological disorder: a systematic review
Frontiers in Psychiatry July 20, 2026 Bruce Tamilson, Michael Chitolie, Jan Coebergh et al.
Functional neurological disorder (FND) is a common and disabling condition with limited effective treatments. This systematic review synthesized evidence on ketamine and esketamine use in FND. Thirteen studies were identified, mostly case reports and small case series. Some patients showed improvement in functional motor symptoms, functional dissociative seizures, and other presentations after receiving ketamine or esketamine. However, interpretation is limited by uncontrolled study designs, heterogeneous diagnoses and outcomes, and potential publication and expectancy bias. Adverse effects were variably reported but generally transient in supervised settings. The evidence is insufficient to establish efficacy, though the data suggest that further prospective controlled trials are justified.