Variability in the COMT gene and modification of the risk of schizophrenia conferred by cannabis consumption.

Introduction: The risk of schizophrenia conferred by cannabis has recently been proposed to be modulated by the Val158Met polymorphism (rs4680) at the COMT gene. To date, these findings have not been replicated in independent samples.

Material And Methods: We tested the potential gene-by-environment interaction between Val158Met genotype at the COMT gene and previous use of cannabis in schizophrenia in 192 healthy controls and 91 inpatients with DSM-IV schizophrenia.