The study assessed the efficacy of a methadone-induced memory retrieval-extinction procedure on heroin craving and relapse. Male participants aged 18-55 years old and prescribed MMT to treat heroin dependence were included in the present study, and randomly assigned to receive methadone, or receive methadone plus 10 minutes plus extinction, or receive methadone plus 6 hours plus extinction. The intervention persisted 3 times per week for 4 weeks. Then the subjects were followed up once a month for cue induced heroin craving and relapse.

In the present study, we explored the effect retrieval-extinction procedure on heroin craving and relapse in heroin addicts using the methadone (a commonly used µ-opioid receptor agonist) instead of heroin as the trigger to reactivate drug memories. The subjects were randomly divided into 3 groups, in which they received methadone alone or extinction sessions 10 min or 6 hours after methadone administration. The extinction sessions were given 3 times per week for 4 weeks, each lasted for 30 min. During the extinction procedure, the subjects were exposed to images, heroin paraphernalia and mimic heroin. Subjective craving, morphine urine test and physiological responses were recorded monthly for 4 months.

Inclusion Criteria:

• met the diagnostic criteria of heroin dependence according to DSM-IV
• were prescribed methadone maintenance treatment (MMT) and took it regularly
• no change in city of residence for at least 1 year
• had normal blood pressure and heart rate
• had negative urine morphine screening test
• primary-school level education
• provide signed consent

Exclusion Criteria:

• other substance abuse(except nicotine)
• had a current or past history of Diagnostic and Statistical Manual of Mental Disorders, 4th Edition（DSM-IV) AxisⅠdisorders
• had clinically evident physical disorders
• neurological signs and/or history of neurological disease
• noncompliance with the procedure