No association between the serotonin transporter gene polymorphism 5-HTTLPR and cyclothymic temperament as measured by TEMPS-A

Abstract

Background: Temperaments are stable personality traits that can be considered subsyndromal risk factors of psychiatric illnesses. The 5-HTTLPR polymorphism of the serotonin transporter gene has been found to be associated with affective temperaments, particularly the cyclothymic temperament, as measured with the Temperament Evaluation of Memphis, Pisa, Paris and San Diego-autoquestionnaire version (TEMPS-A). In this study we have attempted to replicate this finding in a population-based sample which is five times as large as the sample used in the original study.

Methods: The 21 items of the cyclothymic subscale of TEMPS-A was filled in by 691 individuals (404 females, 287 males, 18-40 years) randomly recruited from the general population. DNA was isolated from saliva, and the serotonin transporter polymorphism 5-HTTLPR was genotyped using the polymerase chain reaction and fragment analysis.

Results: No significant association was found between 5-HTTLPR genotype and TEMPS-A score, neither when analysing by an additive allelic model nor when the different genotypes and allelic dominance were examined. Furthermore, no association was observed after gender stratification, or when TEMPS-A was analysed as a dichotomous measure, using a cut-off of ≥11 positive item responses.

Limitations: Although being used in clinical settings, TEMPS-A has not been officially validated in Norway.

Conclusions: This study suggests that there is no association between the 5-HTTLPR polymorphism and cyclothymic temperament as measured by TEMPS-A.