Adolescent cannabis use, psychosis and catechol-O-methyltransferase genotype in African Americans and Caucasians.

Cannabis has been reported as a likely risk factor for the development of psychosis, and a gene × environment interaction with the catechol-O-methyltransferase (COMT) gene has been proposed. Moreover, COMT has been separately linked to affective symptoms in psychosis. Despite a high rate of cannabis abuse and affective symptoms in African Americans, no studies exploring a relationship between COMT and psychosis in this group have been reported. An existing database of psychotic patients with and without adolescent cannabis use/affective symptoms was examined, and chi-square analyses for independence were applied separately for both Caucasians and African-Americans to examine genotype associations with adolescent cannabis use and affective symptoms (past or present). The two subject groups did not differ with respect to the prevalence of adolescent cannabis abuse or presence of affective symptoms. Further study is needed, with non-psychotic controls and larger samples.