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Thomas B. Cooper

Columbia University

2 papers in the library · 382 citations · publishing 2005-2020

Papers

Comparative and Interactive Human Psychopharmacologic Effects of Ketamine and Amphetamine

Archives of General Psychiatry September 1, 2005 John H. Krystal, Edward Perry, Ralitza Gueorguieva et al. 323 citations

Ketamine and amphetamine produce different patterns of psychotic and cognitive effects in healthy people. Ketamine causes perceptual changes, negative symptoms, and memory disruption, while amphetamine triggers hostility, grandiosity, and somatic concern. Both drugs produce positive symptoms and euphoria, but their interaction reveals three patterns: amphetamine reduces ketamine-induced working memory impairment; the drugs additively increase thought disorder, arousal, and euphoria; and their combined effect on psychosis is less than additive. These results suggest that glutamate and dopamine systems contribute differently to psychosis, thought disorder, and euphoria, and that boosting prefrontal dopamine may help cognitive problems linked to glutamate dysfunction.

Assessment of Relationship of Ketamine Dose With Magnetic Resonance Spectroscopy of Glx and GABA Responses in Adults With Major Depression

JAMA Network Open August 12, 2020 Matthew S. Milak, Rain Rashid, Zhengchao Dong et al. 59 citations

A single subanesthetic dose of ketamine produces an antidepressant response in patients with major depressive disorder within hours. In this randomized clinical trial of 38 adults, higher ketamine doses and blood levels correlated with greater improvement on the Hamilton Depression Rating Scale 24 hours later. However, the brain's glutamate+glutamine (Glx) response to ketamine mediated this relationship: lower Glx responses predicted better antidepressant effects. GABA levels did not correlate with antidepressant benefit. Adverse effects were linked to blood levels only in men. The findings suggest that ketamine's antidepressant mechanism involves reducing Glx levels in the ventromedial prefrontal cortex.