A Genetic Variant (COMT) Coding Dopaminergic Activity Predicts Personality Traits in Healthy Elderly

Area of Science:

• Neuroscience
• Behavioral Genetics
• Psychology

Background:

• Previous association studies of the Catechol-O-methyltransferase (COMT) rs4680 gene and personality traits, primarily using the NEO Five Factor Inventory, have yielded inconsistent results, often focusing on younger populations.
• Age-related changes in personality and cortical function may enhance the detectability of genetic associations in older adults.

Purpose of the Study:

• To investigate the association between the COMT rs4680 genotype and personality traits in a large sample of healthy, cognitively normal older adults.
• To explore how genetic variations in COMT influence personality dimensions in the context of aging.

Main Methods:

• Genetic association analyses were performed between the NEO Five Factor Inventory and the COMT rs4680 polymorphism.
• A sample of 616 healthy, cognitively normal older adults (mean age = 69.26 years) was utilized for the study.

Main Results:

• Significant associations were identified: individuals with the GG genotype exhibited lower Neuroticism scores (p = 0.039).
• Participants with the GG genotype also demonstrated higher scores for Agreeableness (p = 0.020) and Conscientiousness (p = 0.006) compared to those with AA or AG genotypes.
• These findings suggest that higher COMT enzymatic activity (GG genotype), associated with lower dopamine levels, correlates with a less neurotic and more agreeable and conscientious personality profile.

Conclusions:

• The study indicates that older adults with the GG genotype of COMT rs4680 may possess a more adaptive personality profile, characterized by reduced Neuroticism and increased Agreeableness and Conscientiousness.
• This aligns with models of dopamine release, suggesting that optimal phasic dopamine release, potentially influenced by the GG genotype despite lower tonic dopamine, contributes to these personality characteristics.