In chronic constriction injury (CCI) of the sciatic nerve, a model of neuropathic pain causes depression-like behavior in animals, and the cannabinoid CB2-selective agonist GW405833 improves immobility and mechanical hypersensitivity, reinforcing the role of the CB2 pathway in nociceptive control in animal models [125]. This evidence concerns the gene CNR2 and major depressive disorder.