The moderating effect of FKBP5 and 5-HTTLPR polymorphisms on the day-level association between drinking to cope motivation and negative affect.

Daily levels of drinking to cope (DTC) have been found to be related to negative outcomes such as increased negative affect, and these effects vary across person. We examined whether daily-level effects of DTC motivation were related to two genetic polymorphisms (rs1360780 in the FKBP5 gene and 5-HTTLPR in SLC6A4) thought to be associated with maladaptive drinking and stress-reactivity. We also examined whether these associations changed during the transition from college to post-college life. Participants (N = 839, 55% women) completed an Internet-based 30-day daily diary during college and again five years later in which they reported their previous night's drinking and drinking motivation, and their current day's negative affect. Saliva was collected at wave 1 to provide DNA for genotyping. The within-person association between nighttime DTC motivation and next-day anxiety and depression was stronger (more positive) for FKBP5 rs1360780 T-allele carriers, compared C/C-allele individuals. We also found that 5-HTTLPR L'/S' subjects (but not S'/S' homozygotes), compared to L'/L' homozygotes, showed stronger positive associations between DTC and anxiety. Results for FKBP5 T-allele carriers are discussed in terms of past findings indicating that such individuals tend to demonstrate increased attention toward stressors, thus possibly intensifying the deleterious effects of DTC-motivated drinking.