Association of serotonin transporter gene polymorphisms with poststroke depression

Abstract

Context: Polymorphisms of the serotonin transporter gene (SERT) have been associated with mental illness. 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.

Objective: To determine whether the 5-HTTLPR, STin2 VNTR, and rs25531 polymorphisms of SERT are associated with poststroke depression (PSD) in stroke survivors.

Design: A case-control study in which stroke survivors were screened for depressive symptoms and assigned to either a depressed group or a nondepressed group.

Setting: Outpatient clinic.

Participants: Seventy-five stroke survivors with PSD and 75 nondepressed stroke survivors.

Interventions: Blood or saliva samples were collected from each participant for DNA extraction and genotyping.

Main outcome measures: The associations between the 5-HTTLPR, STin2 VNTR, and rs25531 polymorphisms and PSD.

Results: Individuals with the 5-HTTLPR s/s genotype had 3-fold higher odds of PSD compared with l/l or l/xl genotype carriers (odds ratio, 3.1; 95% confidence interval, 1.2-8.3). Participants with the STin2 9/12 or 12/12 genotype had 4-fold higher odds of PSD compared with STin2 10/10 genotype carriers (odds ratio, 4.1; 95% confidence interval, 1.2-13.6). An association of rs25531 with PSD was not shown.

Conclusions: The 5-HTTLPR and the STin2 VNTR, but not the rs25531, polymorphisms of SERT are associated with PSD in stroke survivors. This gives further evidence of a role of SERT polymorphisms in mediating resilience to biopsychosocial stress.