Effects of Different Subanesthetic Doses of (S)-Ketamine on Neuropsychology, Psychopathology, and State of Consciousness in Man
Torsten Passie, Matthias Karst, Birgitt Wiese, H. M. Emrich, Udo Schneider
Neuropsychobiology January 1, 2005 DOI: 10.1159/000085724 via OpenAlex
Summary
AI-generated from the abstractThe first neuropsychological study of the S-enantiomer of ketamine, a noncompetitive NMDA antagonist, found that low and high subanaesthetic doses produced only nonsignificant impairment on most cognitive tasks in 12 healthy male volunteers. However, tasks involving divided and sustained attention, along with objective and subjective psychopathology scores, showed significant impairment that increased with dose. These results suggest that ketamine's effects on attention may model aspects of schizophrenia.
Study at a glance
| Characteristics | Randomized placebo-controlled trial Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Healthy male volunteers |
| Intervention | (S)-ketamine |
| Dose | low dose/high dose |
| Topics | Ketamine |
| Keywords | Neuropsychology Psychopathology Schizophrenia object-oriented programming Placebo |
| Citations | 35 |
| Key finding | Subanaesthetic doses of (S)-ketamine produce significant, dose-dependent impairment in divided and sustained attention and psychopathology, but not in most other neuropsychological tasks. |
Abstract
This is the first neuropsychological study using the S-enantiomer of the noncompetitive N-methyl-D-aspartate antagonist ketamine. In 2 randomized placebo-controlled trials we studied effects of two different doses of (S)-ketamine (low dose/high dose) on neuropsychological functions and psychopathology in 12 healthy male volunteers. Impairment was measured via standardized neuropsychological tests. Results indicate that both subanaesthetic doses produce only nonsignificant impairment in most of the tasks. Tasks involving divided and sustained attention as well as scores for objective and subjective psychopathology show significant impairment in a dose-dependent manner. Implications of these findings for the neuropsychology of attention and schizophrenia are discussed.