Association of dopamine receptor D 2 Taq I A polymorphism and cannabis use disorder in L agos, N igeria

Taq I A polymorphism (rs1800497) has been linked to many substance use disorders but there is a shortage of data on cannabis use disorder. N igeria has a huge burden of cannabis use disorder, prompting our investigation of the relation between cannabis use disorder and the Taq I A polymorphism among males in L agos, N igeria. We recruited 106 males with cannabis use disorder based on I nternational C lassification of D iseases, version 10 ( ICD ‐10) and 98 cannabis‐naive males for the study. C annabis use disorder was assessed using the S everity of D ependence S cale ( SDS ) and C annabis U se D isorder I dentification T est ( CUDIT ). Genotyping was done using the R estriction F ragment L ength P olymorphism ( RFLP ). The frequency of the A 1 allele was higher among the cannabis users (57.8%) compared with the nonusers (42.2%). The genotype distribution was found to be in H ardy‐ W einberg equilibrium in both populations. The homozygous A 1 genotype alone contributed 11.8% to the variance in the SDS scores. However, both A 1/ A 1 and A 1/ A 2 genotypes contributed to the variance in the CUDIT scores (10.2% and 5.1%, respectively). In conclusion, the distribution of the A 1 allele among the general population in this study correlates with the previously reported findings in a southwestern N igerian population. We also found that carrying an A 1 allele appears to be a significant predictor of cannabis use disorder. The result suggests that carrying just a single allele of the A 1 is enough to predict cannabis abuse, as shown by the allele association with CUDIT scores. However, double A 1 alleles seem to be necessary for the prediction of dependence.