A Genomewide Association Study of DSM-IV Cannabis Dependence

Despite twin studies showing that 50–70% of variation in DSM-IV cannabis dependence is attributable to heritable influences, little is known of specific genotypes that influence vulnerability to cannabis dependence. We conducted a genomewide association study of DSM-IV cannabis dependence. Association analyses of 708 DSM-IV cannabis dependent cases with 2,346 cannabis exposed nondependent controls was conducted using logistic regression in PLINK. None of the 948,142 SNPs met genomewide significance (p < E −8 ). The lowest p-values were obtained for polymorphisms on chromosome 17 (rs1019238 and rs1431318, p-values at E −7 ) in the ANKFN1 gene. While replication is required, this study represents an important first step towards clarifying the biological underpinnings of cannabis dependence.