Sara Sami - Department of Psychology and Educational Sciences, Al-Zahra University, Tehran, IranDepartment of Educational Psychology, Faculty of Educational Sciences and Psychology, Alzahra University, Tehran, Iran.
Mohammad Effatpanah - School of Medicine, Ziaeian Hospital, International Campus, Tehran University of Medical Sciences, Tehran, Iran.
Afsaneh Moradi - Department of Psychology and Educational Sciences, Al-Zahra University, Tehran, IranDepartment of Educational Psychology, Faculty of Educational Sciences and Psychology, Alzahra University, Tehran, Iran.
Omid Massah - Substance Abuse and Dependence Research Center, University of Social Welfare & Rehabilitation Sciences, Tehran, Iran.

Objectives: The Matrix Model is used for MA dependence in methadone services in Iran, the most populated Persian Gulf country. However, there are no studies of the efficacy of the Matrix Model for MA dependence while in treatment. The present study reports on the efficacy of sixteen weeks of the Matrix Model for MA abstinence and general health.  Methods: There were MA-dependent male (n=۳۰) and female (n=۳۰) patients in the study sites whom received the Matrix Model. The sites included three large methadone clinics in Tehran, Iran during ۲۰۱۵. The Persian versions of the Time Line Follow Back (TLFB) and the General Health Questionnaire-۲۸ (GHQ-۲۸) were completed by each participant at baseline and treatment weeks of four, ten and sixteen. Abstinence from MA was confirmed on the TLFB and with doing urinalyses at the same time. Results: All subjects were daily MA users on the TLFB at baseline. General health was poor among all subjects at baseline. There was no reported subject attrition at baseline. But, ten subjects left the Matrix treatment before the end of week nine and ۲۱ subjects left the Matrix treatment before the end of week ۱۳. At week ۴, only ۲۰% of the subjects were abstinent from MA. At week ten, ۳۵% of the subjects were abstinent from MA while at week ۱۶, ۶۵% of the subjects were abstinent from MA. The Matrix Model led to an increased rate of abstinence from MA (P<۰.۰۰۱) at week ۱۶. Those who completed the treatment were more likely to report improved general health (P<۰.۰۵) than those who did not at week ۱۶. Discussion: The study indicated that the Matrix Model significantly increased the rate of abstinence from MA. But, at week sixteen, subject attrition was high. This issue demands further research.

Dependence, Methamphetamine, Methadone, Matrix model, Treatment