Associations between suicidal ideation and 5-HTTLPR, STin2 VNTR, 5-HTR2a 1438A/G, and 5-HTR2a 102T/C genotypes were estimated using logistic regression models, and gene-gene interactions were investigated using the generalized multifactor dimensionality reduction method after adjustment for potential covariates, including depression.
In people with long-term medical conditions, variants of the 5-HTTLPR and STin2 VNTR polymorphisms of SERT have been shown to confer a heightened vulnerability to comorbid depression.