The Sex Difference in Depression and Anxiety Explained?

A single nucleotide polymorphism (SNP) in the gene for brain-derived neurotrophic factor (BDNF) has been implicated in the development of anxiety (JW Psychiatry Dec 11 2006). The SNP, which causes methionine (met) to be substituted for valine (val) at position 66, results in a reduction of BDNF expression. Moreover, the SNP, carried by about 30% of the white population, may attenuate the ability of estrogen to induce BDNF. Investigators explored the possible role of this SNP in the relatively higher prevalence of anxiety and depression in women after menarche and in the recurrence of depression in association with reproductive events. After inserting the human SNP into mice, they measured performance on several behavioral tests that model a…