1. ¹Department of Psychiatry, University Hospital of Fort de France, Fort de France, Martinique, French West Indies
2. ²INSERM E117, Université Paris 5, SHU Hôpital Sainte Anne, Paris, France

Correspondence: Dr N Ballon, Department of Psychiatry, University Hospital of Fort de France, BP 632, 97221 Fort de France, Martinique, French West Indies. E-mail: ballon@informatique2000.fr

Received 22 October 2004; Revised 8 September 2005; Accepted 4 October 2005; Published online 29 November 2005.

Abstract

Owing to their agonist action on dopaminergic systems, cannabinoids may play a major role in substance dependency and schizophrenia. We examined the (AAT)n triplet repeat polymorphism nearby the CNR1 gene, which encodes human cannabinoid (CB1) receptor, in a male Afro-Caribbean population. The allelic and genotypic distributions were significantly different in non-schizophrenic cocaine dependents (n=97), schizophrenic cocaine dependents (n=45) and matched controls (n=88) (P<10^-4). The frequency of the (AAT)12 repeat allele was increased in non-schizophrenic cocaine dependents and schizophrenic cocaine dependents vs controls (25.3 and 26.7 vs 5.7%) (P<10^-4). Our results support that the (AAT)n polymorphism nearby the CNR1 gene could be associated with predisposition to cocaine dependency.