CNR1 and major depressive disorder: The wide and heterogeneous distribution of CB1 receptors in the brain [30], and recent findings of CB2 receptors not only in microglia but also in neurons [31], at the same time suggests that strengthening of the ECS tone by mild activation of central CB1 and CB2 is closely related with an emotional (anxiety, depression, PTSD) wellbeing, while overstimulation of CB1 activity induces psychotic symptoms [32].