Adding extended-release methylphenidate to psychological intervention for treatment of methamphetamine dependence: A double-blind randomized controlled trial

Background: Iran has been faced with an emerging epidemic of methamphetamine (MA) use during recent years. No effective pharmacotherapy has been identified for MA treatment; and psychological interventions are the only available effective treatment. The aim of this study is to investigate the efficacy and safety of extended-release methylphenidate (ER-MTP) for the treatment of methamphetamine dependence. Methods: Sixty-two people with methamphetamine dependence, according to DSM-IV-TR, were randomly assigned to either fixed-dose extended-release methylphenidate (ER-MTP) (60 mg per day) or placebo for 12 weeks. All participants received twice-weekly cognitive behavioral treatment for stimulant dependence. Recent drug use and craving level were measured using weekly rapid urine test and craving visual analogue scale, respectively. The severity of addiction was measured using the Addiction Severity Index at baseline and study completion. Assessment of MA withdrawal was conducted using Amphetamine Withdrawal Questionnaire and Amphetamine Selective Severity Assessment at baseline, day 3, week 1, week 4 and week 12. Depression and high-risk behaviors assessed with the Beck Depression Inventory and the high-risk behavior questionnaire at baseline, weeks 4 and 12 of the study. SPSS software version 22 was used for data analysis and p<0.05 was considered significant. Results: Percent of weekly MA negative urine tests was not significantly different between groups during the course of the study (p=0.766). Two groups showed similar retention rates. Changes in MA craving, withdrawal, addiction severity, depression and high-risk behaviors were not significantly different between groups. No serious adverse event was observed. Conclusion: Our finding did not show the superiority of fixed-schedule ER-MTP over placebo when added to an intensive biweekly outpatient psychosocial treatment. Further studies using individually tailored flexible-dose regimes might provide new insights regarding the safety and efficacy of psychostimulant maintenance treatment for MA dependence.