Objectives: Alcohol use disorders (AUD) act as a risk factor for smoking relapse, and tobacco dependent (TD) subjects with comorbid AUD experience more withdrawal symptoms compared to TD subjects without AUD or other psychiatric comorbidities. Our aim was to investigate whether drinking behaviour in the past 12 months and smoking relapse due to alcohol use in TD subjects was associated with polymorphisms flanking the TTC12/ANKK1/DRD2 region since associations have been found between these genes and AUD and TD as separate disorders.
Methods: 380 TD subjects were assessed for alcohol use and relapse to smoking. Subjects were genotyped for polymorphisms located in the TTC12/ANKK1/DRD2 region.
Results: Associations were found between ANKK1 haplotype rs4938015C_rs11604671A and age of onset of daily smoking, as well as with hazardous drinking. No genetic association was found with smoking relapse due to alcohol consumption.
Conclusions: Our findings suggest that TD subjects who present earlier age at onset and carry this haplotype may have a higher risk for developing an alcohol use disorder.