Purpose: Considering the decreasing age of addiction and the many problems faced by addicts, the present research was conducted with the aim of presenting a causal model of bias towards drugs in students based on the academic failure and hyperactivity and attention deficit with the mediating role of hopelessness feelings. Method: The current research in terms of purpose was applied and in terms of implementation method was descriptive from type of correlation. The research population was all the junior and senior high school students of one district of Mashhad city in the 2020-2021 academic years, which number of 310 people of them were selected as a sample by cluster random sampling method. The tools of the current research were the questionnaires of addiction potential, academic failure, hyperactivity and attention deficit and hopelessness, which whose psychometric indicators were confirmed in previous researches and in this study. Data were analyzed by structural equation modeling method in SPSS version 24 and AMOS version 24 software. Results: The findings of the present study showed that the causal model of bias towards drugs in students based on the academic failure and hyperactivity and attention deficit with the mediating role of hopelessness feelings had a good fit. Also, the variable of academic failure on the hopelessness feelings and bias towards drugs, the variable of hyperactivity and attention deficit on the hopelessness feelings and the variable of hopelessness feelings on the bias towards drugs had a direct and significant effect (P<0.05), but the variable of hyperactivity and attention deficit on the bias towards drugs hadn’t a direct and significant effect (P>0.05). In addition, academic failure and hyperactivity and attention deficit had an indirect and significant effect on the bias towards drugs with the mediating of hopelessness feelings (P<0.05). Conclusion: The results indicated the effective role of academic failure and hyperactivity and attention deficit with the mediating of hopelessness feeling on bias towards drugs. Therefore, the planners and specialists of cultural and educational activities of adolescents in order reduce to bias towards drugs can seek to design and implement programs to reduce academic failure, hyperactivity and attention deficit and hopelessness feelings.
