Serotonin plays a central role in mood regulation and the development of depressive disorders. The serotonin transporter, the primary regulator of serotonin levels, presents genetic variants that affect its functionality.
Aim: To study whether functional bi-allelic 5-HTTLPR or tri-allelic 5-HTTLPR/rs25531 polymorphisms in the serotonin transporter gene are associated with the diagnosis of depression.
Methods: The Composite International Diagnostic Interview (CIDI-10) and sociodemographic and psychosocial questionnaires were applied to 969 primary care center patients aged 18 to 75 years to establish the diagnosis of depression. A saliva sample was obtained for DNA extraction and genetic analysis.
Results: No association was found between the diagnosis of depression in the last 12 months and risk genotypes grouped for 5HTTLPR or 5-HTTLPR/rs25531. Of the sociodemographic variables, female sex and the number of different forms of violence experienced in childhood proved to be predictors of depression in the sample studied.
Conclusions: In this study, 5HTTLPR/rs25531 polymorphisms, independent of the bi- or tri-allelic analysis performed, did not prove to be risk factors for depression. In turn, we corroborated that female sex and childhood traumatic events are associated with an increased risk of developing a major depressive episode.