Associations among the NEO Personality Inventory, Revised and the serotonin transporter gene-linked polymorphic region in elders: effects of depression and gender

Objective The short variant of the serotonin transporter gene-linked functional polymorphic region (5-HTTLPR) has been associated with personality traits related to anxiety, hostility, and depression. We attempted to replicate findings suggesting a positive relation between the short allele variant of 5-HTTLPR and Neuroticism, and a negative association between the short allele variant and Agreeableness. Methods Participants in the present study were 103 geriatric depressed patients and 99 non-depressed age matched controls. Depression status and gender were examined as potential modifiers of the association between 5-HTTLPR and personality. Results Neuroticism was associated with allele frequency such that individuals with the short variant of the allele (ss or sl, group S) were significantly lower on Neuroticism (P<0.04) compared with individuals with the long allele variant (group L), a pattern opposite to that of previous reports. The association did not vary by clinical group (depressed or controls) but was conditional on gender (P<0.01): the mean Neuroticism for males in group S was 48.2, whereas the mean Neuroticism for males in group L was 55.9; and the mean Neuroticism for females did not differ by allele group. In the total sample, Agreeableness was not associated with allele frequency; however, there was a significant allele group x clinical group x gender interaction (P<0.01). Conclusions The present findings failed to replicate prior work suggesting that the short variant of the 5-HTTLPR allele is associated with higher Neuroticism and lower Agreeableness. Psychiatr Genet 13:13-18 (C) 2003 Lippincott Williams Wilkins.