Two　types　of　cannabinoid　(CB)　receptors　have　been　described　in　the　human　body:　CB1　and　CB2　receptors.　CB1　receptor　distribution　may　be　related　to　the　cannabinoid　functions　of　memory　and　cognition　regulation　as　well　as　motor　control.　In　addition,　the　endocannabinoid　system　(ECS)　related　to　CB1　receptors　may　be　involved　in　human　emotion　regulation,　especially　depression　occurrence.　Indeed,　CB1　receptors　are　all　distributed　in　depression　associated　neuroanatomical　structures　and　neural　circuits.　Both　animal　experiments　and　clinical　studies　have　demonstrated　that　impairment　of　the　ECS　pathway　is　present　in　depression　models　and　patients,　and　application　of　both　CB1　receptor　agonists　and　anandamide　(cannabinoid-like　substance)　degradation　inhibitors　produce　similar　biochemical　and　behavioral　effects　as　antidepressants.　These　findings　provide　a　solid　basis　for　understanding　the　ECS　role　in　the　formation　and　development　of　depression.　Therefore,　it　can　be　inferred　that　the　ECS　may　have　an　important　function　in　both　depression　treatment　and　the　effects　of　antidepressants.