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Cannabis, fear and post-traumatic stress disorder (PTSD)

Exploring the role of cannabinoids as a treatment for PTSD

This study explores the role of cannabinoids as possible adjunct treatments to PTSD exposure therapy in two related experimental studies looking at fear extinction.

Project overview

Clinical Research

In PTSD, it is thought that the hyperconsolidation of fear memories and failure of memory extinction systems make aversive memories intrusive and inescapable. A compelling body of evidence suggests that endogenous cannabinoid systems are at the centre of a complex biochemical cascade that modulates the consolidation and extinction of fear memories. Here we explore the role of cannabinoids as possible adjunct treatments to PTSD exposure therapy.

The approach uses a Pavlovian fear conditioning paradigm to install aversive memories in volunteers using a semi-predictable, 100dB, white noise burst, followed by an experimental model of exposure therapy, where the fear memory is extinguished through repeated exposure to fear cues without the white noise burst.

In this study, we explore the effects of recreational cannabis use (hence, predominantly a study of the effects of THC) on a person’s vulnerability to develop a lasting fear response, as well as the effects of THC use on a person’s capacity to remove the fear response in exposure therapy.

Positive findings of cannabinoids facilitating fear extinction will provide safety and efficacy data to support future plans to move into clinical populations with a cannabinoid drug trial for people suffering from PTSD.

Preclinical Research

We seek to identify phytocannabinoids and full-spectrum extracts with therapeutic potential to treat PTSD using a preclinical disease model. There are no drugs specifically approved for the treatment of PTSD. Presently SSRIs are the mainstay of treatment, however they are modestly effective. Thus there is a need to develop better therapies for PTSD. Performing preclinical studies will help identify lead cannabinoid compounds for clinical development. Moreover, they will instruct our clinical researchers on the best way to design their studies.

Cannabis users study
Ethics approved: January 2017
Recruitment to cannabis users study commenced: February 2017
Total of 30 people recruited to date
Anticipated completion of recruitment: June 2017
Analysis and write up by: October 2017

Associate Professor Jonathon Arnold
Professor Iain McGregor
Professor Nicholas Glozier

Marieke Graat
Hannah Gutmann
Associate Professor Hamish MacDougall
Dr Christine Rabinak
Professor Jan Ramaekers
Professor Nicholas Lintzeris
Professore Paul Haber
Victor Trevino

Clinical, experimental human psychopharmacology, double-blind, placebo-controlled, experimental human psychopharmacology study of novel drug

The Lambert Initiative

Ethics approvals have been obtained and recruitment is ongoing. A total of 30 people have been recruited to date (as at May 2017)


This study is now closed for recruitment.

Refer to our clinical studies page for upcoming opportunities to participate.