(Gelernter et al. 1994). The reasons for these associations are unclear, given the lack of information about the doses that were ingested. The findings may indicate that drug users with the 9-repeat allele of the 3′-UTR VNTR polymorphism are more sensitive to stimulant-induced psychotic phenotypes, or, alternatively, they may have ingested higher doses of the drug to achieve their desired effect, thus increasing their risk for psychosis.
