Neuroticism and polymorphisms in the serotonin transporter gene.

BACKGROUND There is evidence for an association between two different polymorphisms of the human serotonin transporter gene (5-HTT) and the personality trait of neuroticism and affective disorder. METHODS We studied the association between neuroticism and polymorphisms in the 5HTT-linked promoter region and in a variable number tandem repeat region (VNTR) of the 5-HTT gene in 204 people aged over 60 derived from a random sample of men and women in the general population. Approximately half of the subjects were in the top 20% of neuroticism scorers and half in the bottom 20%. RESULTS There were no significant differences in allelic or genotypic frequencies between the high and low neuroticism scorers. There was highly significant linkage disequilibrium between the two 5-HTT gene polymorphisms, and haplotype analysis showed no association between neuroticism level and haplotype. CONCLUSIONS Reports of an association between two 5-HTT gene polymorphisms and the personality trait of neuroticism are not supported by these results.