For example, new research suggests one gene-gene interaction model for the increased risk of depression among heavy alcohol users.
- What typically happens is that a gene called TACE activates a second gene, called MTHFR, which produces an enzyme involved in metabolism of folate, which helps determine the level of folate in the body.
- If MTHFR is not producing the enzyme at the typical level, folate levels are reduced. Reduced folate levels are associated with depression.
- Excessive alcohol exposure has been shown to suppress the TACE gene, which then activates less MTHFR, which then makes less enzyme. This cascade results in less folate being metabolized, which has been associated with increased incidence of depression.