Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, National Institutes of Health, NIMH-NIH, 10 Center Drive, Bldg. 10, Room 7-5545, Bethesda, MD 20892, USA. Electronic address: hiroe.hu@nih.gov.
2 papers in the library · 3 citations · publishing 2025-2026
A systematic review of 30 studies suggests that ketamine and, to a lesser extent, d-cycloserine may enhance empathy and prosocial behavior. These glutamate receptor modulators appear to alter self- and other-perception by changing activity in brain regions linked to empathetic concern and mentalizing—the ability to understand one's own and others' thoughts and feelings. The findings point toward potential therapeutic applications for conditions involving impaired empathy and prosocial behavior, such as mood, neurodevelopmental, psychotic, and personality disorders.
People with both major depression and post-traumatic stress disorder (PTSD) have lower baseline levels of copeptin, a stable marker of vasopressin secretion, and a blunted reduction in copeptin after a single low-dose ketamine infusion compared to those with depression alone. Copeptin levels were unrelated to depression diagnosis or symptom severity of depression, anxiety, PTSD, anhedonia, suicidal ideation, or childhood trauma, but higher copeptin was linked to verbal aggression, an association weakened by PTSD. These findings point to a possible biological subtype of reduced vasopressin activity in co-occurring depression and PTSD, suggesting copeptin may serve as a peripheral biomarker for central vasopressin-driven circuits in neuropsychiatric disorders.