The Model of Substance Use Tendency Based on the Behavioral Inhibition/Activation System with the Mediating Role of Psychological Capital

Objective: This study aimed to investigate a model of substance use tendency based on the behavioral inhibition/activation system (BIS/BAS) with the mediating role of psychological capital among secondary school students in Tehran. Methods and Materials: This was a descriptive-correlational study using structural equation modeling (SEM). The statistical population included all secondary school students in Tehran in spring 2024. A multi-stage cluster sampling method was used to select 400 students. Data were collected using three questionnaires: BIS/BAS scales, substance use tendency questionnaire, and psychological capital questionnaire. Data analysis was conducted using AMOS version 22. Findings: Path analysis showed that behavioral inhibition system had a significant negative relationship with substance use tendency (β=−0.42, p<0.001), while the behavioral activation system had a significant positive relationship with it (β=0.35, p<0.001). Psychological capital had a significant negative effect on substance use tendency (β=−0.30, p<0.001). The indirect effects through psychological capital were also statistically significant and confirmed by the Sobel test. Model fit indices indicated a good fit (RMSEA=0.06, CFI=0.93, GFI=0.90). Conclusion: The proposed model demonstrated good fit, indicating that psychological capital plays a significant mediating role in the relationship between behavioral systems and substance use tendency. Enhancing psychological capital may serve as an effective intervention strategy to reduce substance use tendencies among adolescents.