The Val158Met polymorphism has been linked to a broad range of psychiatric disorders including anxiety and mood disorders [2]. Although anxiety and depression both are influenced by several genes in combination with environmental factors, association studies with large samples of subjects are appropriate for searching susceptibility genes with minor effects on these disorders [3]. A large European multicenter study including 1512 participants reported an association between the Val/Val genotype and major depression with early onset [3], but conflicting results have been found in other studies with fewer participants [4]. Similarly, inconsistent findings have also been reported in studies evaluating the relationship between the Val158Met polymorphism and anxiety [5-7]. Ethnic heterogeneity and gender specificity may have influenced on the inconclusive results [8].
