The Association of Catechol-O-Methyl-Transferase and Interleukin 6 Gene Polymorphisms with Posttraumatic Stress...

Posttraumatic stress disorder (PTSD) is a disorder that occurs in some people who have experienced a severe traumatic event. Several genetic studies suggest that gene encoding proteins of catechol-O-methyl-transferase (COMT) may be relevant for the pathogenesis of PTSD. Some researchers suggested that the elevation of interleukin-6 (IL6) correlates with major depression and PTSD. The aim of this study was to investigate whether the single nucleotide polymorphisms COMT rs4680 (Val158Met) and IL6 rs1800795 are associated with PTSD and contribute to the severity of PTSD symptoms.

This study comprised 747 participants that experienced war between 1991 and 1999 in the South Eastern Europe conflicts. COMT rs4680 (Val158Met) and IL6 rs1800795 genotypes were determined in 719 participants (369 with and 350 without PTSD). The Mini International Neuropsychiatric Interview (M.I.N.I.), the Clinician Administrated PTSD Scale (CAPS) questionnaire and the Brief Symptom Inventory (BSI) were used for data collection.

Regarding the COMT gene polymorphism, the results of the regression analyses for BSI total score were significant in the lifetime PTSD group in the dominant (P=0.031) and the additive allelic model (P=0.047). Regarding the IL6 gene, a significant difference was found for the recessive model predicting CAPS total score in the lifetime PTSD group (P=0.048), and indicated an association between the C allele and higher CAPS scores. n the allelic, genotypic and rezessive model, the results for BSI total score were significant in the lifetime PTSD group (P=0.033, P=0.028 and P=0.009), suggesting a correlation of the C allele with higher BSI scores.

Although our nominally significant results did not withstand correction for multiple tests they may support a relevance of the COMT (Val158Met) and IL6 rs1800795 polymorphism for aspects of PTSD in war traumatized individuals.