Dopamine Receptor Polymorphism (DRD4 -521C/T) and Responsivity to Emotional Films and Social Challenge
Limited research has investigated the impact of the dopamine receptor D4 (DRD4) gene on affective responses to positive and social stimuli. Research shows variability in DRD4 impacts levels of social bonding under the influence of alcohol and reward processing while gambling, suggesting variation in DRD4 impacts emotions concerning social or rewarding stimuli. The goal of the current study is to examine how DRD4 -521C/T polymorphism (rs1800955) predicts emotional responses to film clips and simulated social interaction. In the current study, one sample of undergraduate students, n = 119, were exposed to emotional film clips and a separate sample of undergraduate students, n = 121, completed a within-subject version of the Cyberball task which simulates peer rejection and acceptance. DNA was extracted from saliva samples in both samples, purified, quantified, and finally diluted to a concentration of 5 ng/μl. Repeated measures ANOVA tested for differences in emotional responsivity by task type and segment. Participants with the C/C genotype reported higher levels of positive affect when compared to other genotypes when exposed to all film clips, F(2, 117) = 2.73, p = .069, or all stages of Cyberball, F(2, 119) = 3.02, p = .052. In both samples, there was no effect between genotype and negative emotion. These results were controlled for current symptoms of depression. Results suggest a potential buffering effect because levels of positive affect in individuals with the C/C genotype of the DRD4 -521C/T polymorphism are higher when these individuals are exposed to social rejection or acceptance.