Study aim: To compare the effectiveness of the integrated codependency intervention, Community Reinforcement and Family Training (CRAFT), and psychoeducation based on the Matrix protocol on codependency levels and quality of life among spouses of individuals with substance use disorder. Design: A randomised block clinical trial with three arms of 14 participants each (total 42). To reduce bias, block randomisation was performed using the SealedEnvelope website. After informed consent, participants randomly select a sealed envelope, assigning them to one of the groups. Allocation of envelopes to study centers is done by simple randomization. Settings and conduct: Select substance use treatment clinics in Isfahan and Tehran Participants/Inclusion and exclusion criteria: Minimum age of 18 years, having a spouse undergoing treatment for substance use, no current or past substance use disorder or acute psychosis based on DSM-5 criteria, scoring at least 52.6 on the Spann-Fisher questionnaire, and willingness to participate with informed consent. Intervention groups: 1)Integrated codependency intervention consisting of 11 sessions covering case history, motivational interviewing, understanding addiction and maladaptive behaviours, codependent roles, breaking dysfunctional family cycles, managing obsessive thoughts, problem solving, and emotion regulation. 2)Standard CRAFT therapy; 3)Psychoeducation based on the Matrix model. All groups have an equal number and duration of sessions. Main outcome variables: Codependency scale in participants