Although human meta-analytic studies have shown that individuals homozygous for the Met allele have an increased risk for developing anxiety disorders [10, 16, 18], and Chen et al. [1] found an anxiety-like phenotype in Met/Met mice compared to Val/Val controls, our previous studies in mice showed no differences in genotypes in light-dark box measure of anxiety [19], while BDNF het rats showed an anxiety phenotype in the open field but not EPM [21]. This evidence concerns the gene BDNF and anxiety disorder.