The Investigation of Executive Functions in Patients under Methadone and Buprenorphine Maintenance Treatment

Despite acknowledged evidence of clinical and research on the executive functional impairment of methadone and buprenorphine, still no evidence of comparative study with other drugs and therapeutic approaches is found. This study aimed to evaluate the executive function in opiate users, and those who are under methadone, buprenorphine and abstinence therapy.
The study is a cross-sectional survey. Five groups of 31 patients treated with methadone, buprenorphine, abstinence, and opioid abusers and the control group of addicted patients referring to the treatment centers in Semnan and ordinary people were randomly selected. Data were collected by performing computer version of Stroop and Working Memory Tests on subjects. Multivariate analysis of variance was used to analyze the data.
The results indicate greater impairment of working memory and response inhibition in opiate abusers, methadone addicts, buprenorphine and abstinence compared to the control group. Deeper investigation showed that patients treated with buprenorphine had better results compared to other treatment groups in working memory and Stroop test, although this superiority was not statistically significant in some cases.
Although both methadone and buprenorphine leads to a reduction in executive function, but better performances of buprenorphine was marked even in compare to abstinence treatment. It seems that more emphasis should be done on the use of buprenorphine.