factors related to addiction treatment motivations; validity and reliability of an instrument

background: understanding the motives and reasons for drug treatment is very important. this study aimed to develop a psychometric evaluation to determine the reasons for addiction treatment among outpatients referred to addiction treatment clinics. methods: this cross-sectional validation study included five phases (i) item generation (ii) making an initial questionnaire (iii) content validity (iv) reliability analysis and (v) structure validity. addiction treatment motivations were identified by reviewing literatures and interviews with 21 stakeholders. a 30-item questionnaire was used for data collection and a random sample of 300 participants completed the questionnaire. the data were analyzed using content validity (cvr &cvi;), internal consistency (chronbach’s alpha coefficient) and exploratory factor analysis (efa) by spss version 16 software. results: with exploratory factor analysis, 22 items that were remaining jointly explained 60.6% of the variance observed. inconsistency assessment, cronbach’s coefficient (α) of items was 0.9. items with cvis and cvrs greater than 0.84, remained and factor loading cut off ≥ 0.5 as valid items. they were loaded into four factor solution for the questionnaire, namely: family factors, threats, friend’s factors and self-efficacy. conclusions: this study suggestes a reliable and valid instrument with four factors related to motives of addiction treatment.