title: Drug use and misuse in operant pain patients.
mesh_terms: D003216:Conditioning, Operant; D006801:Humans; D010146:Pain / Q000188:drug therapy* / Q000523:psychology; D011619:Psychotropic Drugs / Q000627:therapeutic use; D019966:Substance-Related Disorders / Q000523:psychology*
chemical_list: D011619:Psychotropic Drugs