Memory Reconsolidation Blockade for Treating Drug Addiction

The treatment involves administering propranolol, a medication indicated for treating high blood pressure. Propranolol is hypothesized to reduce the strength of drug or alcohol cravings (an integral factor involved in relapse), specifically when memories of substance use are recalled. In this study, propranolol or a placebo will be administered to patients participating in a drug or alcohol rehabilitation facility once a week over three or six weeks. After receiving propranolol or placebo, strong memories associated with substance craving are recalled by asking participants to read aloud a summary of a substance use experience. The investigators hypothesize that participants who receive propranolol will report fewer and less intense drug or alcohol cravings than participants who receive the placebo or treatment-as-usual.

Trial Objectives: To test the feasibility of reconsolidation blockade as an adjunct treatment for reducing drug or alcohol cravings in individuals diagnosed with a substance dependence or substance abuse disorder and participating in a drug rehabilitation program.

Study Design and Duration: This study will be a 3 to 6 week, randomized, double-blind trial involving participants with a DSM-IV-TR diagnosis of substance dependence or abuse. Consented participants meeting enrolment criteria will receive a dose of propranolol (1mg/kg) or placebo ninety minutes before undergoing a brief memory reactivation procedure twice a week for a three-week period (or once a week for a six week period, depending on the participants availability) as an adjunct to their usual drug rehabilitation treatment. Participants will be randomized to one of two treatment arms (i.e. placebo group + treatment as usual, or propranolol group + treatment as usual) and remain in that arm for the duration of the study. Participants from the placebo arm will be offered the opportunity to continue receive open-label propranolol treatment for another 3-6 weeks following the double-blind phase of the study. A four-month follow-up assessment will also be conducted.

Eligibility Criteria:
Inclusion Criteria:

* Male or female subjects between 18 and 65 years of age
* Female subjects must not be of child bearing potential or be non pregnant and be established on an acceptable method of birth control or be one who abstains from sex
* Diagnosis of substance dependence or substance abuse disorder within a 1-month period prior to screening
* Currently enrolled in a drug rehabilitation treatment program for marijuana, cocaine, heroin, other opiates, benzodiazepine, alcohol, or amphetamine addictions
* Individuals who consent to remain abstinent from all drugs of abuse (except nicotine) and from alcohol for 24 hours prior to enrolment and for the duration of the study
* Individuals treated with the following medications must be on stable doses for at least 1-month prior to the screening visit and during the entire study: anxiolytics, sedatives, hypnotics, antidepressants, antipsychotics
* Individuals taking Selective Serotonin Reuptake Inhibitors (SSRIs) or Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) must accept to skip their morning dose the day of each study visit
* Individuals shall not start taking new medications on a regular basis during the study
* Fluency in French or English

Exclusion Criteria:

* Systolic blood pressure \<100 mm Hg
* Cardiac rhythm below 55 beats per minute
* A medical condition that contraindicates the administration of propranolol
* Previous adverse reaction to, or non-compliance with, beta-blocker
* Current use of medication that may involve potentially dangerous interactions with propranolol.
* Women who are pregnant or breast feeding
* Past or present bipolar disorder or psychosis
* Individuals with current dependence on any substance besides, cocaine, heroin, other opiates, benzodiazepines, amphetamines, marijuana, or alcohol
* Subjects judged as being at significant risk of self injurious/suicidal or violent/homicidal behavior
* Participation in another drug trial within 30 days prior to the screening visit or during the study
* Any condition that can significantly affect the absorption of the study medication
* Presence of any clinical condition that might interfere with the interpretation of the efficacy and safety results