Study population
psychiatric
DISORDER
Opioid users were identified by a psychiatrist at the Ahvaz drop-in center, affiliated with Ahvaz Jundishapur University of Medical Sciences in January 2020, and a randomized controlled trial (RCT) was conducted with all of the opioid users who were registered and had medical records in the center. The inclusion criteria used in the study were (a) addiction to opioids based on ICD-11, (b) a period of methadone maintenance therapy (MMT), and (c) no prior history of CBT. The exclusion criteria were (a) having a medical or psychological disorder that explained the symptoms, (b) a concomitant medical or psychiatric disorder that required treatment or hospitalization, (c) inability to provide informed consent, and (d) leaving the center before the completion of CBT treatment. For the current study, forty opioid users were randomly divided into two equal groups using a table of random numbers (