Article

Psychological effects of ketamine in healthy volunteers. Phenomenological study.

Benito Menni CASM, Barcelona, Spain.
The British Journal of Psychiatry (impact factor: 6.62). 09/2006; 189:173-9. DOI:10.1192/bjp.bp.105.015263 pp.173-9
Source: PubMed

ABSTRACT The psychosis-inducing effect of ketamine is important evidence supporting the glutamate hypothesis of schizophrenia. However, the symptoms the drug produces have not been described systematically.
To examine the effects of ketamine in healthy people using a structured psychiatric interview.
Ketamine (200 ng/ml) or placebo was administered by continuous infusion to 15 healthy volunteers. Symptoms were rated using the Present State Examination, the Thought, Language and Communication Scale and the Scale for Assessment of Negative Symptoms.
Ketamine induced a range of perceptual distortions, but not hallucinations. Referential ideas were seen in nearly half the sample. There were only mild and infrequent ratings on the thought disorder scale. Affective flattening and alogia were seen in some volunteers.
Ketamine does not reproduce the full picture of schizophrenia. The main point of similarity concerns referential thinking. Phenomena resembling negative symptoms are also seen, but the distinction of these from the drug's sedative effects requires further elucidation.

0 0
 · 
0 Bookmarks
 · 
27 Views
  • Source
    Article: Reduced dorsal prefrontal gray matter after chronic ketamine use.
    Yanhui Liao, Jinsong Tang, Philip R Corlett, Xuyi Wang, Mei Yang, Hongxian Chen, Tieqiao Liu, Xiaogang Chen, Wei Hao, Paul C Fletcher
    [show abstract] [hide abstract]
    ABSTRACT: Use of ketamine as a recreational drug is spreading rapidly among young people all over the world. Epidemiological studies have linked chronic ketamine use with a number of problems, including cognitive impairments, bladder dysfunction, and ketamine-related death. However, little is known about the long-term effects of ketamine use on brain structure and function. We used voxel based morphometry in conjunction with statistical parametric mapping on the structural magnetic resonance images of ketamine-dependent (n = 41) and drug-naive control individuals (n = 44) to assess differences in gray matter volume between the two groups. We observed significant decreases in gray matter volume in bilateral frontal cortex (left superior frontal gyrus and right middle frontal gyrus) of ketamine users in comparison with control subjects (p < .05 corrected for multiple comparisons at cluster-level). Duration of ketamine use was negatively correlated with gray matter volume in bilateral frontal cortex, whereas the estimated total lifetime ketamine consumption was negatively correlated with gray matter volume in left superior frontal gyrus. We have demonstrated a reduction in frontal gray matter volume in patients after chronic ketamine use. The link between frontal gray matter attenuation and the duration of ketamine use and cumulative doses of ketamine perhaps suggests a dose-dependent effect of long-term use of the drug. Our results have important connotations for the clinical picture that is likely to emerge with the growing recreational use of ketamine and is also relevant to the status of the drug as a model for schizophrenia.
    Biological psychiatry 10/2010; 69(1):42-8. · 8.93 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

15 healthy volunteers
 
Communication Scale
 
continuous infusion
 
drug's sedative effects
 
elucidation
 
full picture
 
glutamate hypothesis
 
infrequent ratings
 
Ketamine
 
main point
 
negative symptoms
 
perceptual distortions
 
Present State Examination
 
similarity concerns referential
 
structured psychiatric interview
 
Symptoms
 
thought disorder scale