MDD patients with lower BDNF concentrations were more likely to suffer frequent somatic complaints (20), and remitted patients with MDD under Selective Serotonin Reuptake Inhibitors (SSRIs) treatment had less severe somatic symptoms compared to non-remitters (21), that is, the efficacy of SSRIs can predict somatic symptoms severity at the endpoint. This evidence concerns the gene BDNF and major depressive disorder.