title: An expanded self-medication hypothesis based on cognitive-behavioral determinants for heroin abusers in Taiwan: a cross-sectional study.
abstract: BACKGROUND
  This study proposed and examined an expanded self-medication hypothesis (eSMH) model based on cognitive behavioral determinants, including the direct effects of negative emotional states, positive outcome expectancies and refusal self-efficacy on heroin use, and the mediating roles of positive outcome expectancies and refusal self-efficacy between negative emotional states and heroin use.
  
  
  METHODS
  A total of 360 male heroin abusers were recruited from a drug abuse treatment center in Taiwan. Participants were asked to complete a set of questionnaires on frequency of heroin use, anxious/depressive mood, positive outcome expectancies, and refusal self-efficacy. Structural equation modeling was used to examine the eSMH model.
  
  
  RESULTS
  Results showed that the eSMH model displayed proper goodness-of-fit. Positive outcome expectancies and negative emotional status were significant predictors of heroin use, whereas refusal self-efficacy was not a significant predictor. Additionally, positive self-efficacy was a mediator between negative emotional status and heroin use.
  
  
  CONCLUSIONS
  Results support a reduced eSMH model and suggest a significant role of positive self-efficacy in the relationship between negative affective states and heroin use. This relationship should be examined in the longitudinal study, and should be given clinical consideration in treatment of individuals struggling with heroin abuse and negative affective states.
authors.affiliation: Department of Psychology, Kaohsiung Medical University, Kaohsiung, Taiwan. kunhualee627@gmail.com
authors.forename: Kun-Hua Sam
authors.initials: KH
authors.lastname: Lee
authors.forename: Sarah
authors.initials: S
authors.lastname: Bowen
authors.forename: Tian P S
authors.initials: TP
authors.lastname: Oei
authors.forename: Cheng-Fang
authors.initials: CF
authors.lastname: Yen
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology; D003071:Cognition; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology; D004644:Emotions; D006556:Heroin Dependence / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D020377:Self Efficacy; D012651:Self Medication / Q000523:psychology*; D011795:Surveys and Questionnaires; D013624:Taiwan