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.
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.
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×clinical group×gender interaction (P<0.01).
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.