Association of the STin2 polymorphism of the serotonin transporter gene with a neurocognitive endophenotype in major depressive disorder

Abstract

Background: The aim of our study was to investigate the association of STin2 polymorphism and cognitive dysfunction in major depression.

Methods: 71 patients with major depression and 99 controls were genotyped for STin2. All depressive subjects and 30 controls also completed tests measuring neurocognitive performance.

Results: We found a significantly higher frequency of the STin2.10/Stin2.10 homozygous genotype in the depressed group compared to controls. In the depressed group subjects with at least one copy of the 10-repeat allele showed decreased interference threshold in Stroop III compared to patients without the 10-repeat allele. Average performance of the depressed group without the 12-repeat allele was significantly weaker in the Rey Auditory Verbal Learning Test working memory and recall tasks compared to patients having at least one copy of the 12-repeat allele.

Conclusion: Our results suggest that the presence of STin2.10 and absence of STin2.12 allele may be related to a possible genetic endophenotype for characteristic cognitive dysfunctions detected in MDD.