Our study could not confirm any clear association between the Val158Met polymorphism and anxiety or depression measured by HADS. However, a number of functional polymorphisms in- or close to the COMT gene have been described, and some recent studies have looked at multiple single nucleotide polymorphisms (SNPs) and different COMT haplotypes in relation to psychiatric phenotypes [38,39], and interaction between the COMT gene and other genes [26,33]. Due to lack of financial- and personnel resources we did not assess additional SNPs within the COMT gene or in other genes. As a consequence, we were unable to evaluate the influence of haplotypes of the COMT gene or possible interactions with other genes on HADS.
