BDNF and major depressive disorder: Binding to central or peripheral endocannabinoids receptors produces different responses (Raichlen et al., 2012), and can produce analgesia (Agarwal et al., 2007), stimulate reward centers in the brain to reduce anxiety and enhance euphoria (Dietrich and McDaniel, 2004), improve mood and lower depression by increasing the expression of BDNF (Tantimonaco et al., 2014), and finally modulate the release of dopamine (increased) and GABA (decreased) (Raichlen et al., 2012).