Genetic associations with performance on a behavioral measure of distress intolerance

Both theory and empirical evidence support possible associations between two candidate genetic polymorphisms (SLC6A4 5-HTTLPR l/s and COMT Val¹⁵⁸Met - rs4680 variants) and emotion-regulation difficulties. One particular form of emotion-regulation difficulty, distress intolerance, has been measured using a behavioral assessment in youth; data indicate a relationship with poor psychological functioning. No prior study has investigated genetic influences on emotion-regulation difficulties in youth. As part of a larger longitudinal study on adolescent risk behaviors, 218 10-14 year-old youths from the metropolitan Washington, D.C., area completed a measure of distress intolerance, the Behavioral Indicator of Resilience to Distress (BIRD), and provided saliva samples for DNA extraction and genotyping. Results indicate that those with one or two copies of the s allele of the 5-HTTLPR polymorphism were more likely to perform poorly on the task (i.e., choose to quit) than were those homozygous for the l allele. Participants who were Val allele carriers of the COMT Val¹⁵⁸Met polymorphism were also more likely to quit the task compared to Met homozygotes. A summative risk allele score was created to combine the two polymorphisms, and each risk allele was associated with a 1.75 fold increased likelihood of quitting the task. Exploratory analyses revealed that emotional abuse moderated the relationship between the 5-HTTLPR and BIRD performance, as well as the genetic risk allele and the BIRD. This is the first investigation of genetic predictors of a behavioral measure of tolerance to distress. Results suggest that distress tolerance is at least partially regulated by specific genetic variants. Implications are discussed.