Effectiveness of Abstinence-Based Residential Treatment Centers on Executive Functions of Individuals with Substance Use Disorder Under Treatment in Kerman

Abstract

The present study aimed to determine the effectiveness of abstinence-based residential treatment on improving executive functions among individuals with substance use disorder undergoing treatment in Kerman City. This quasi-experimental study employed a pretest–posttest design with a control group. The statistical population consisted of 420 clients receiving treatment in abstinence-based residential centers in Kerman in 2024, from whom 40 participants were purposively selected and randomly assigned to experimental and control groups. The experimental group received a 90-day abstinence-based residential treatment protocol approved by the Iranian Welfare Organization, while the control group remained on a waiting list. Executive function deficits were assessed using the Barkley Deficits in Executive Functioning Scale (BDEFS). Data were analyzed using analysis of covariance (ANCOVA) after confirming statistical assumptions including normality and homogeneity of variances. ANCOVA results indicated significant posttest differences between the experimental and control groups across all executive function components after controlling for pretest scores (p<0.05). Abstinence-based treatment significantly reduced deficits in time self-management, self-organization and problem-solving, self-control and behavioral inhibition, self-motivation, and emotional self-regulation. Large effect sizes were observed, with the strongest effects reported for self-organization/problem-solving (η²=0.74) and self-control/inhibition (η²=0.726), demonstrating substantial cognitive and behavioral improvements associated with the intervention. Abstinence-based residential treatment represents an effective comprehensive intervention for enhancing executive functioning in individuals with substance use disorder and may contribute to strengthened self-regulation capacities, improved rehabilitation outcomes, and reduced relapse risk.