Val158Met polymorphism in the COMT gene is associated with hypersomnia and mental health-related quality of life in a Colombian sample

The identification of genes that are risk factors for major depressive disorder remains a main task for global psychiatric research. The Catechol-O-methyltransferase (COMT) gene has been an important candidate risk factor for several psychiatric disorders. Previous studies have shown that a functional polymorphism (Val158Met) in this gene has an effect on several brain circuits and endophenotypes of psychiatric relevance. The aim of this study was to explore the association of a functional polymorphism in the COMT gene with psychological distress, sleep problems and health-related quality of life. Two hundred seventy young Colombian subjects (mean age: 21.3 years; range: 18-57 years) completed the Patient Health Questionnaire-9, the Perceived Stress Scale, the Oviedo Sleep Questionnaire and the 12-Item Short-Form Health Survey and were genotyped for the Val158Met polymorphism (rs4680) in the COMT gene. A linear regression analysis, adjusting for potential confounding factors, was carried out. Subjects that were Met carriers (Val/Met and Met/Met genotypes) showed higher scores for hypersomnia (p = 0.001) and lower scores for mental health-related quality of life (p = 0.007), these associations remained significant after correcting for multiple testing. These findings support the hypothesis of a broad effect of the Val158Met polymorphism in the COMT gene on several dimensions of behavior and neuropsychiatric symptoms.