The effects dopamine related genes on decision dynamics and psychiatric dimensions

Dopaminergic function is implicated in different aspects of cognition and affect. However, the role of dopamine in decision process is not fully understood. We investigated the association between the dopaminergic (DA) gene polymorphisms (i.e., COMT, DRD2, DARPP-32) with the latent variables of the decision-process as well as neuropsychiatric states estimated from factor analysis. 82 students were tested in a perceptual decision-making task with different difficulties and filled out five neuropsychiatric scales. The accuracy and response times gathered from the decision-making task were modeled with a hierarchical Bayesian drift-diffusion model to estimate how the core latent parameters of the decision process changed between different gene polymorphisms. Met/Met allele of COMT gene, which is associated with increased DA in prefrontal cortex had less cautious decision making and more efficient evidence integration when compared to Val carriers. Individuals with this polymorphism also had higher obsessive-compulsive and anxious-depressive scores. There were no significant associations with polymorphisms of DRD2 and DARPP-32 genes. Our results suggest a modulatory (through decision threshold) and enhancing (through the rate of sensory evidence integration) role of prefrontal dopamine related gene COMT polymorphism in perceptual decision making. Our results associate Met/Met allele with an increase in obsessive-compulsive and anxious-depressive scores.