Hinderk M. Emrich

2 papers in the library · 27 citations · publishing 2003-2006

Papers

Effects of different subanaesthetic doses of (S)-ketamine on psychopathology and binocular depth inversion in man

Journal of Psychopharmacology January 1, 2003 Torsten Passie, Matthias Karst, Mathias Borsutzky et al. 27 citations

The NMDA neurotransmitter system's role in psychoses is not fully understood, but NMDA antagonists like phencyclidine and ketamine induce psychotic states similar to schizophrenia. Binocular depth inversion, a visual illusion impaired in psychotic states, was tested in 12 healthy male volunteers using stereoscopic pictures of natural and artificial objects. Two subanaesthetic doses of the psychotomimetic S-enantiomer of ketamine were compared with placebo. Despite dose-dependent subjective and objective psychopathology, no significant impairment of binocular depth perception occurred with (S)-ketamine. The findings suggest implications for memory, perception formation, and bottom-up processing in ketamine model psychosis and schizophrenia.

DOI: 10.1177/0269881103017001698 Ketamine Psychotomimetic Psychopathology Psychosis +14

Disturbances of visual information processing in early states of psychosis and experimental delta-9-tetrahydrocannabinol altered states of consciousness.

Schizophrenia Research December 1, 2006 Dagmar Koethe, Christoph W Gerth, Miriam A Neatby et al.

In people with schizophrenia, in the prodromal phase, and in healthy volunteers given synthetic delta-9-tetrahydrocannabinol (THC), performance on a test of visual information processing (the Binocular Depth Inversion Illusion Test) was similarly impaired, and all three groups differed significantly from healthy controls who received no drug. On the Brief Psychiatric Rating Scale, the THC-treated group and the prodromal group did not differ significantly, while both differed from the schizophrenia group and from controls. The findings suggest that THC-induced altered states can model psychotic disorders, especially their prodromal states, and help explain the pro-psychotic effects of high-THC cannabis.

DOI: 10.1016/j.schres.2006.07.023 Full text