title: Locus of control and need for control among heroin users.
mesh_terms: D000281:Administration, Intranasal; D003932:Heroin / Q000008:administration & dosage; D006556:Heroin Dependence / Q000523:psychology*; D006801:Humans; D007389:Internal-External Control; D009042:Motivation
chemical_list: D003932:Heroin