Problem gambling is the subclinical form of pathological gambling and both are characterized by difficulties in the limiting of money and time spent on gambling. Genetic and personality factors have been implicated in gambling disorders (PG). As PG is classified as an impulse-control disorder, the serotonin (5-HT) system has been suggested to be involved. We sought to better understand the complex relationship between personality traits, PG, and 5-HT genes. We investigated ten 5-HT candidate genes for association with PG and personality traits. We also examined personality traits for association with PG. We found that MAOA and HTR3A haplotypes were associated with Agreeableness and Conscientiousness personality domains, PG was associated with high Neuroticism and low Conscientiousness scores, and the MAOA gene may play a role in PG. Our findings contribute to the better understanding of how 5-HT genes may be involved in the neurobiological mechanisms underlying PG and personality.

Problem gambling is the subclinical form of pathological gambling and both are characterized by difficulties in the limiting of money and time spent on gambling. Genetic and personality factors have been implicated in gambling disorders (PG). As PG is classified as an impulse-control disorder, the serotonin (5-HT) system has been suggested to be involved. We sought to better understand the complex relationship between personality traits, PG, and 5-HT genes. We investigated ten 5-HT candidate genes for association with PG and personality traits. We also examined personality traits for association with PG. We found that MAOA and HTR3A haplotypes were associated with Agreeableness and Conscientiousness personality domains, PG was associated with high Neuroticism and low Conscientiousness scores, and the MAOA gene may play a role in PG. Our findings contribute to the better understanding of how 5-HT genes may be involved in the neurobiological mechanisms underlying PG and personality.