About this trial
Cannabis is the most commonly used psychoactive substance in Canada (Lowry \& Corsi, 2020). A sub-group of cannabis users develop a condition known as Cannabis Use Disorder (CUD), which is defined as a regular pattern of cannabis use that causes performance difficulty at work, school and relationships (Hasin et al., 2013). A review of current treatments available for CUD indicate the lack of a pharmacological and psychological treatment with high success rates, which highlights the importance of exploring potential psychosocial interventions for the treatment of CUD. Given the evidence of psilocybin's therapeutic potential in the treatment of substance use disorders (de Veen et al., 2017), we aim to conduct a study using psilocybin-assisted-psychotherapy in the treatment of CUD. The study aims to evaluate the feasibility, safety, tolerability and potential therapeutic effect of 2 doses \[25 mg\] of psilocybin administered as part of an 8-week Motivational Enhancement Therapy (MET) and supportive therapy. This trial will be the first to evaluate the potential treatment effects of psilocybin on symptoms of CUD.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Signed Informed Consent Form.
Able to show documentation of identity.
Fluent in speaking and reading English and able to complete rating scales and assessments.
Between the ages of 18 to 65.
Disqualifiers
Meet DSM-5 criteria for lifetime history of bipolar disorder, schizophrenia, or other psychotic disorders, personality disorders, delirium, dementia and amnesic and other cognitive disorders, or are in a current agitated state.
Have first-degree biological relatives (parents or full siblings) with past or present history of schizophrenia, bipolar disorder and any other psychosis.
Meet DSM-5 criteria for panic disorder or seizure disorders.
Meet DSM-5 criteria for dependence of any substance other than cannabis or tobacco in the past 6 months.
Trial design
Single group
Treatments tested in this trial
Psilocybin combined with Psychotherapy
DrugThe intervention consists of a 9-week treatment protocol that is based on supportive psychotherapy and Motivational Enhancement Therapy. Overall, the therapy course includes 8 motivational enhancement therapy sessions and two experimental drug sessions.
Treatment groups
Trial outcomes
Primary outcomes
Incidence of spontaneously reported adverse events and serious adverse events from baseline to the nine-week endpoint
frequency, type and severity of outcomes are recorded
Percent of recruited participants who discontinue or are lost to follow up before completing the 9-ween treatment protocol
frequency of cases of withdrawal and lost to follow up are documented and a percent is calculated based on the total number of participants recruited in this study.
Secondary outcomes
Feasibility measured by number of individuals who express interest by contacting the study team, percent of individuals who are screened as eligible to those who contact the study, percent of those who complete the trial to those who are enrolled
Reported in frequency and percentages
Efficacy a: frequency and amount of cannabis use, as measured by the Timeline Follow Back from baseline to the nine-week end point
This is measured using the Timeline Follow Back tool
Efficacy b: Severity of symptoms associated with Cannabis Use Disorder as measured by Self-Reported Symptoms of Cannabis Use Disorder from baseline to 9 week endpoint
Self-Reported Symptoms of Cannabis Use Disorder
Efficacy c: Changes in Urinary Cannabinoids from baseline to the nine-week endpoint
Urinary Cannabinoid Test
Other outcomes
severity of symptoms of craving, withdrawal, anxiety, depression and functional impairment
Measured using Marijuana Withdrawal Checklist, Marijuana Craving Questionnaire, Patient Health Questionnaire - 9, Generalized Anxiety Disorder, Sheehan Disability Scale
Sponsors and contacts
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McMaster University
Lead sponsor
Center for Medicinal Cannabis Research
Collaborator
Peter Boris Centre for Addictions Research (PBCAR)
Collaborator