No association between catechol-O-methyltransferase val158met polymorphism and alexithymia

Objectives: Reduced concentrations of dopamine in prefrontal brain structures may play a role in alexithymia. Dopamine degradation in the orbitofrontal cortex is regulated by catechol-O-methyltransferase (COMT), and a functional single nucleotide polymorphism of the COMT gene, Val158Met, has been related to psychiatric illness. This study examines the association between the COMT Val158Met gene polymorphism, and alexithymia. Methods: 120 healthy students and 120 patients with mental disorders were genotyped for the COMT Val158Met polymorphism. Additionally, the Toronto Alexithymia Scale (TAS-20) was administered. Results: COMT genotype did not show a significant correlation with the TAS-20 in either group. Conclusions: COMT Val158Met polymorphism alone does not seem to be a major factor in alexithymia in healthy students. This is true even if patients with mental disorders covering a broader range of alexithymia are included. Thus, other genes, possibly interacting with cultural, environmental, and developmental factors, may be implicated.