In the past decade opioid overdose deaths have nearly doubled in both the USA and Australia, now killing more people in the USA each year than car crashes, firearms and breast cancer. In Australia, the majority of opioid overdose deaths are related to pharmaceutical opioids. The severe physical withdrawal syndrome that emerges after cessation of opioid use is a significant contributor to individuals transitioning to problematic use and is a major hurdle to recovery attempts. The endogenous-cannabinoid and opioid systems are deeply intertwined, with numerous lines of evidence suggesting cannabinoids may offer a breakthrough treatment for opioid addiction. In this project we are using gold-stand preclinical models to assess the potential of cannabinoids for treating opioid withdrawal.
Research team: Associate Professor Jennifer Cornish (Macquarie University); Professor Iain McGregor, Associate Professor Jonathon Arnold (Lambert Initiative, University of Sydney)
This project is investigating whether cannabinoids have therapeutic efficacy in treating methamphetamine addiction. We are testing various phytocannabinoids in a preclinical model of addiction in which rats voluntarily self-administer methamphetamine.
Exploring cannabinoid solutions to the opioid addiction crisis
This is a collaboration between the Lambert Initiative for Cannabinoid Therapeutics, University of Sydney, Sydney Local Health District and South East Sydney Local Health District.
This is an ongoing collaboration between the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney and Macquarie University.
Participants will receive one of the interventions (a daily fixed dose of an oral CBD or placebo) across a five day inpatient stay at either of the study sites; Royal Prince Alfred Hospital or Sydney Eye Hospital, both in Sydney. The objective of this trial is assess the clinical effectiveness, tolerability and cost-effectiveness of a fixed-dose of CBD during acute alcohol withdrawal in improving withdrawal outcomes for alcohol dependence relative to placebo.
Research Team: Dr Michael Bowen (Lambert Initiative, University of Sydney)
Ethics approval was obtained, and the study was conducted in accordance with the ethical guidelines of the Hamilton Integrated Ethics Board (project ID 4556). Participants provided verbal and written informed consent and were able to withdraw from the study at any time. Our study procedures and analyses are reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines .
Older age of first cannabis use was associated with lower odds of opioid use during treatment. Younger age of onset of substance use has been associated with polysubstance use, higher severity of substance use disorder, and worse outcomes in treatment [33, 34]. Additionally, the deleterious effects of cannabis use on neurodevelopment with younger age of onset may lead to worse outcomes in adulthood .
Missing 3-month urine data affected 22 participants (2%) and reasons for missingness included transfer to another clinic (n = 8), failed treatment (n = 12), completed treatment (n = 1), and incarceration (n = 1; see Fig. 1). Due to the low percentage of missing data, missingness was handled by available case analysis. We also planned one a priori subgroup analysis by sex, based on our previous finding of sex differences in cannabis use and its impact in MAT in a previous study .
Past-month cannabis use was not associated with more or less opioid use during treatment. For patients who use cannabis, we identified specific characteristics of cannabis use associated with differential outcomes. Further examination of characteristics and patterns of cannabis use is warranted and may inform more tailored assessments and treatment recommendations.
The health and policy landscapes of substance use and addiction are changing as jurisdictions around the world legalize recreational cannabis while facing an ongoing opioid crisis. With legalization, the prevalence of cannabis use is expected to rise [1, 2], raising particular concerns about its impact on individuals with existing psychiatric comorbidity. Understanding the impact of cannabis use for patients with opioid use disorder (OUD) in the light of high rates of concurrent use is important . The continuing opioid crisis across North America is reflected in ongoing increases in opioid overdose deaths , as well as increased enrolment in medication-assisted treatment (MAT) [5, 6] , including treatment with methadone and buprenorphine–naloxone. MAT reduces opioid cravings and withdrawal to support abstinence from opioid use, and has been shown to improve outcomes including overall productivity and quality of life [7, 8]. However, outcomes in MAT are variable [9, 10], and ongoing examination of the impact of modifiable factors such as psychiatric comorbidity and polysubstance use on treatment is important.
Results: At the start of their quit attempt, 70% of participants smoked cannabis at least weekly (40% daily), averaging [SD] 2.73 [1.95] joints daily; 60% were heroin dependent. Subjects with heroin dependence were significantly older at the start of their quit attempt (22.9 [3.6] vs. 19.1 [2.9] years), were significantly less likely to report withdrawal irritability/anger/aggression (22% vs. 58%), restlessness (0% vs. 25%), or physical symptoms (6% vs. 33%), or to meet diagnostic criteria for DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th edition) cannabis withdrawal syndrome (6% vs. 33%), and had shorter duration of abstinence (29.6 [28.7] vs 73.7 [44.1] months) than those without heroin dependence.
Methods: Thirty inpatients (57% men) completed the Marijuana Quit Questionnaire (MJQQ) after completing acute heroin detoxification treatment in Saint Petersburg, Russia. The MJQQ collected data on motivations for quitting, withdrawal symptoms, and coping strategies used to help maintain abstinence during their most “serious” (self-defined) quit attempt made without formal treatment outside a controlled environment.
Background: Cannabis use is common among opioid-dependent individuals, but little is known about cannabis withdrawal in this population.
Conclusion: Cannabis users with opioid dependence are less likely to experience cannabis withdrawal, suggesting that opiate use may prevent or mask the experience of cannabis withdrawal. RESULTS should be considered preliminary due to small convenience sample and retrospective data.