The relationship between cigarette smoking and depression vulnerability: Effects of the serotonin transporter gene

People with current or past depression are more likely to have been regular smokers at some point in their lives. Smokers who have had experiences of depression are also less likely to quit. Attempts to understand this relationship and the potential underlying mechanisms are important insofar as they can help treatment efficacy for this group of smokers that appears to have particular difficulty maintaining smoking cessation. Prior research has suggested that different genetic variations might affect the relationship between smoking and depression. For instance, previous findings indicated that people with a short, less efficient, serotonin transporter gene have a stronger relationship between smoking and neuroticism than those with a long genotype. This study examined whether people with a short serotonin transporter genotype would have a stronger relationship between depression vulnerability and smoking behavior than those with the long genotype. In this sample (N = 487), depression vulnerability was associated with the tendency to be a current smoker, the likelihood of having ever been a smoker, and the tendency to smoke to reduce negative affect. However, participants with the short serotonin transporter genotype did not have stronger relationships between depression vulnerability and smoking variables. Discussion centered on possible reasons for varying results across conceptually similar studies.