title: Narcotic analgesics, addiction and endorphins.
mesh_terms: D000701:Analgesics, Opioid / Q000627:therapeutic use*; D004723:Endorphins / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D010146:Pain / Q000378:metabolism; D019966:Substance-Related Disorders / Q000209:etiology
chemical_list: D000701:Analgesics, Opioid; D004723:Endorphins