Serotonin transporter gene polymorphisms and chronic illness of depression

Clinical course of depression is variable. The serotonin transporter gene is one of the most studied genes for depression. We examined the association of serotonin transporter gene polymorphisms with chronicity and recurrent tendency of depression in Korean subjects. This cross-sectional study involved 252 patients with major depression. Patients were genotyped for s/l polymorphisms in 5-HTT promoter region (5-HTTLPR), s/l variation in second intron of the 5-HTT gene (5-HTT VNTR intron2). Chronicity was associated with 5-HTTLPR. Patients with l/l had higher rate of chronicity than the other patients (l/l vs s/l or s/s; odds ratio, 4.45; 95% confidence interval, 1.59-12.46; P=0.005; logistic regression analysis). Recurrent tendency was not associated with 5-HTTLPR. Chronicity and recurrent tendency were not associated with 5-HTT VNTR intron2. These results suggest that chronic depression is associated with 5-HTTLPR.