Opiate use is a serious health concern in Iran, the most populous Persian Gulf country (
1). However, there are few studies of the CBT effectiveness in the treatment of regular opiate use. Most of the studies have focused on psychostimulant users (
9,
10). To date, the current study is the first research of the CBT effectiveness in the treatment of regular opiate use on a stable methadone dose. More studies are needed to evaluate the CBT effectiveness among this group.
The study resulted indicated that the OTI score related to regular opiate use significantly declined after the CBT provision and the result remained stable in the treatment group at follow-up. This was the largest effect size in this study. Similar studies in Australia and the USA indicated that illicit drug use was significantly reduced after the CBT provision and the treatment effectiveness remained stable up to six months (
9,
10,
17).
The study indicated that the readiness to reduce opiate use showed an increase after the CBT provision. The result sustained at follow-up but no change was found in the control group. Nonetheless, the effect size was small. Furthermore, the study indicated that the severity of opiate dependence moderately declined after the CBT provision, sustained at follow-up but no change was found in the control group. A study of illicit drug users indicated that after the CBT provision, the severity of drug dependence significantly declined in the CBT group while the control group showed no significant change (
9). A study in Australia indicated that four sessions of CBT significantly increased readiness to change illicit drug use and reduced the severity of drug dependence (
17). A study in Thailand demonstrated the efficacy of CBT in the treatment of illicit drug use and relapse (
18). The CBT effectiveness in increasing readiness to reduce opiate use and reducing the severity of opiate dependence needs further investigation. Further studies with more samples of regular opiate users are needed to assess the long-term CBT effectiveness in improving these problems.
One of the main positive aspects of this study is that we had no participant attrition. Similar studies in the USA and Australia indicate high rates of participant attrition (
19-
21). The lack of attrition is related to this issue that the participants were retained in methadone treatment and came to the study sites every day to receive methadone. Furthermore, there was a self-reported good relationship between each participant and the research staff. Studies indicate that the high participant attrition rate is a serious problem in the effective provision of CBT (
19). However, an appropriate therapeutic relationship and high qualifications of psychologists in the provision of CBT sessions can reduce the attrition rate (
20). Lack of attrition rate indicates high client engagement in the study procedure, reduced bias and increased generalizability of the study findings (
19,
22,
23). The relationship between attrition rates and high qualifications of psychologists in the effective CBT delivery deserves more research.
The current study has several limitations. First, the study was limited to one follow-up. This was because of limited time and cost restriction. Further studies with more samples of Persian men and women are needed to evaluate the CBT effects. Conducting a study with a six month follow-up is suggested.