EFFECTS OF KETAMINE ON THOUGHT-DISORDER, WORKING-MEMORY, AND SEMANTICMEMORY IN HEALTHY-VOLUNTEERS

Background: The N-methyl-D-aspartate receptor antagonist, ketamine, pr oduces a clinical syndrome of thought disorder perceptual distortion, and cognitive impairment. Methods: We have administered ketamine to he althy volunteers to characterize the formal thought disorder and speci fic memory dysfunction associated with ketamine. Ten healthy volunteer s underwent a double-blind, placebo-controlled, ketamine infusion (0.1 2 mg/kg bolus and 0.65 mg/kg/hour). Thought disorder was evaluated wit h the Scale for the Assessment of Thought, Language and Communication. Cognitive resting involved working and semantic memory tasks. Results : Ketamine produced a formal thought disorder, as well as impairments in working and semantic memory. The degree of ketamine-induced thought disorder significantly correlated with ketamine-induced decreases in working memory and did not correlate with ketamine-induced impairments in semantic memory. Conclusions: This study characterizes the formal thought disorder associated with ketamine and may suggest that ketamin e-induced deficits in working memory are associated with ketamine-indu ced thought disorder. Published 1998 Society of Biological Psychiatry.