How are COMT and sleep related?

COMT (catechol-O-methyltransferase) is a key enzyme in the degradation of dopamine, norepinephrine, and epinephrine. The common Val158Met polymorphism (rs4680) affects enzyme activity: Val carriers have higher activity, Met carriers lower. Studies suggest that Met/Met individuals (slower breakdown) tend to have better sleep quality, longer sleep duration, and fewer sleep disturbances, possibly due to higher prefrontal dopamine tone. However, effect sizes are small and not consistently replicated. Val carriers are more vulnerable to cognitive impairment after sleep deprivation and may experience greater sleep fragmentation. Interactions with stress and caffeine intake further modulate the relationship. Evidence is moderate – based on observational studies and experimental sleep deprivation paradigms. Direct clinical recommendations cannot be derived. Consumer DNA tests like MyBody-X may report this variant, but its predictive value for individual sleep is limited. A focus on overall sleep hygiene remains more impactful than genotype-based adjustments.