COMT Val158Met moderation of cannabis-induced psychosis: a momentary assessment study of ‘switching on’ hallucinations in the flow of daily life
Article first published online: 19 SEP 2008
Copyright © 2008 The Authors. Journal Compilation © 2008 Blackwell Munksgaard
Acta Psychiatrica Scandinavica
Volume 119, Issue 2, pages 156–160, February 2009
How to Cite
Henquet, C., Rosa, A., Delespaul, P., Papiol, S., Faňanás, L., Van Os, J. and Myin-Germeys, I. (2009), COMT Val158Met moderation of cannabis-induced psychosis: a momentary assessment study of ‘switching on’ hallucinations in the flow of daily life. Acta Psychiatrica Scandinavica, 119: 156–160. doi: 10.1111/j.1600-0447.2008.01265.x
- Issue published online: 11 JAN 2009
- Article first published online: 19 SEP 2008
- Accepted for publication August 15, 2008
- psychotic disorders;
- Catechol-o-methyltransferase gene
Objective: A functional polymorphism in the catechol-o-methyltransferase gene (COMT Val158Met) may moderate the psychosis-inducing effects of cannabis. In order to extend this finding to dynamic effects in the flow of daily life, a momentary assessment study of psychotic symptoms in response to cannabis use was conducted.
Method: The experience sampling technique was used to collect data on cannabis use and occurrence of symptoms in daily life in patients with a psychotic disorder (n = 31) and healthy controls (n = 25).
Results: Carriers of the COMT Val158Met Val allele, but not subjects with the Met/Met genotype, showed an increase in hallucinations after cannabis exposure, conditional on prior evidence of psychometric psychosis liability.
Conclusion: The findings confirm that in people with psychometric evidence of psychosis liability, COMT Val158Met genotype moderates the association between cannabis and psychotic phenomena in the flow of daily life.