Effects of ∆9-tetrahydrocannabinol on aversive memories and anxiety: a review from human studies.
Ana Maria Raymundi, Thiago R Da Silva, Jeferson M B Sohn, Leandro J Bertoglio, Cristina A J Stern
BMC Psychiatry August 26, 2020 DOI: 10.1186/s12888-020-02813-8 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Randomized Peer reviewed |
|---|---|
| Population | Healthy human volunteers and patients with posttraumatic stress disorder (PTSD) |
| Interventions | THC Cannabidiol (CBD) |
| Topics | Cannabis CBD Anxiety |
| Keywords | Fear extinction Memory reconsolidation |
| Key findings | The authors conclude that current evidence from healthy humans and PTSD patients supports low-dose THC, or THC combined with CBD, as able to suppress anxiety and aversive memory expression without significant adverse effects. They report that low doses of THC can enhance the rate of aversive memory extinction and reduce anxiety, while effects on aversive memory reconsolidation remain unknown. |
Abstract
Posttraumatic stress disorder (PTSD) may stem from the formation of aberrant and enduring aversive memories. Some PTSD patients have recreationally used Cannabis, probably aiming at relieving their symptomatology. However, it is still largely unknown whether and how Cannabis or its psychotomimetic compound Δ9-tetrahydrocannabinol (THC) attenuates the aversive/traumatic memory outcomes. Here, we seek to review and discuss the effects of THC on aversive memory extinction and anxiety in healthy humans and PTSD patients. Medline, PubMed, Cochrane Library, and Central Register for Controlled Trials databases were searched to identify peer-reviewed published studies and randomized controlled trials in humans published in English between 1974 and July 2020, including those using only THC and THC combined with cannabidiol (CBD). The effect size of the experimental intervention under investigation was calculated. At low doses, THC can enhance the extinction rate and reduce anxiety responses. Both effects involve the activation of cannabinoid type-1 receptors in discrete components of the corticolimbic circuitry, which could couterbalance the low "endocannabinoid tonus" reported in PTSD patients. The advantage of associating CBD with THC to attenuate anxiety while minimizing the potential psychotic or anxiogenic effect produced by high doses of THC has been reported. The effects of THC either alone or combined with CBD on aversive memory reconsolidation, however, are still unknown. Current evidence from healthy humans and PTSD patients supports the THC value to suppress anxiety and aversive memory expression without producing significant adverse effects if used in low doses or when associated with CBD. Future studies are guaranteed to address open questions related to their dose ratios, administration routes, pharmacokinetic interactions, sex-dependent differences, and prolonged efficacy.
Comparable studies
Other systematic reviews and meta-analyses on cannabis for anxiety, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Medicinal cannabis for psychiatric disorders: a clinically-focused systematic review | 2020 | Systematic review | |
| Cannabis, a cause for anxiety? A critical appraisal of the anxiogenic and anxiolytic properties | 2020 | Systematic review | |
| What are the psychological effects of using synthetic cannabinoids? A systematic review Synthetic cannabinoid users, natural cannabis users, and non-users from 17 studies | 2019 | Systematic review | |
| “Noids” in a nutshell: everything you (don’t) want to know about synthetic cannabimimetics | 2014 | Systematic review and descriptive analysis | |
| Cannabis and Anxiety: A Critical Review | 2024 | Systematic review |
Citations in the library
Cited by 5
- Psychedelics: A review of their effects on recalled aversive memories and fear/anxiety expression in rodents Neuroscience & Biobehavioral Reviews September 20, 2024
- Effects of acute Δ9 -tetrahydrocannabinol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice Research Square December 29, 2022
- Cannabis: Drug of Abuse and Therapeutic Agent, Two Sides of the Same Coin. Revista de investigacion clinica; organo del Hospital de Enfermedades de la Nutricion 2023
- Psychotropic Effects of Cannabis Plant-Based Therapeutics, Volume 1 2023
- Adolescent exposure to delta-9-tetrahydrocannabinol and ethanol heightens sensitivity to fear stimuli. Behavioural Brain Research October 11, 2021
Cites 36
- Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing Archives of General Psychiatry 2009
- Inverted U-Shaped Dose-Response Curve of the Anxiolytic Effect of Cannabidiol during Public Speaking in Real Life Frontiers in Pharmacology May 11, 2017
- Acute Effects of a Single, Oral dose of d9-tetrahydrocannabinol (THC) and Cannabidiol (CBD) Administration in Healthy Volunteers Current Pharmaceutical Design September 12, 2012
- Neurophysiological and subjective profile of marijuana with varying concentrations of cannabinoids Behavioural Pharmacology September 1, 2005
- Δ-9-Tetrahydrocannabinol and Cannabidiol produce dissociable effects on prefrontal cortical executive function and regulation of affective behaviors Neuropsychopharmacology November 27, 2018
and 31 more in the library