Citation

Henquet C, Rosa A, Delespaul PAEG, Papiol S, Faňanás L, van Os J, Myin‐Germeys I. Acta Psychiatr. Scand. 2009; 119(2): 156-160.

Copyright

(Copyright © 2009, John Wiley and Sons)

DOI

10.1111/j.1600-0447.2008.01265.x

PMID

unavailable

Abstract

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.