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.