What role does MTHFR play in stress?

MTHFR encodes methylenetetrahydrofolate reductase, a key enzyme in folate and homocysteine metabolism. Through methylation, it influences the synthesis of neurotransmitters like serotonin and dopamine, which are involved in stress regulation. Some studies suggest that certain MTHFR variants (e.g., C677T) are associated with elevated homocysteine and a modestly increased risk for stress-related disorders such as depression or anxiety. However, effect sizes are small, and the evidence is primarily mechanistic or from GWAS associations. There is no robust evidence that MTHFR testing alone provides clinically meaningful prediction of stress responses. Individual stress resilience is shaped by many factors: environment, lifestyle, and other genes. An MTHFR result should not be viewed as deterministic. Supplementation with active folate (5-MTHF) is sometimes recommended, but its benefit for stress is not well established. Beware of exaggerated marketing claims. The predictive value of consumer DNA tests for MTHFR and stress is limited.