Should addiction researchers be interested in psychedelic science?

As recently noted by Strauss, Bright and Williams [1], while much of the Western world has been experiencing a renaissance in research into ‘psychedelic science’ over the past decade [2], there has been no such research conducted in Australia. In Europe and the USA, studies have been conducted into lysergic acid diethylamide (LSD) that have improved our understanding of brain function [3] and reduced existential anxiety associated with dying [4], while psilocybin-assisted psychotherapy has shown promise as an intervention for treatment of refractory depression [5]. Psilocybin-assisted therapy has also been shown to reduce depression and anxiety among people with end-stage cancer [6], with two recent RandomisedControlled Trials (RCT) showing significant improvements in quality of life [7,8]. In collaboration with the researchers involved in this research, the Heffter Institute is in discussions with the US Food and Drug Administration (FDA) about commencing Phase III multisite trials. Meanwhile, 3,4-methylenedioxymethamphetamine (MDMA) is proving efficacious as an adjunct to psychotherapy in the treatment of post-traumatic stress disorder (PTSD) [9–12]. This new research is occurring at prestigious institutions such as New York University, University of California, Los Angeles, Johns Hopkins University and Imperial College London, following a 30 year embargo on psychedelic research that commenced when President Nixon declared his ‘War on Drugs’. We believe that addiction researchers worldwide should be interested in these developments, for several reasons. First, there are indications that psychedelicassisted therapies might be effective in improving success rates in the treatment of substance use disorders. It is hypothesised that the mechanism of action might involve mystical states that have been shown to be reliably produced in an RCT of psilocybin [13]; the personal significance of these effects was maintained at 14 month follow up [14], including positive changes in personality [15]. The neurological basis of these effects is proposed to be a reduction of blood flow in the default mode network [3]. In an open-label trial of 15 people examining psilocybin-assisted psychotherapy for the treatment of tobacco addiction, 80% of participants remained abstinent at 6 month follow up [16]. In contrast, an RCT of varenicline [17], the most efficacious pharmacotherapy for smoking cessation [18], found that only 25.5% of participants were abstinent at 12 months. This team at Johns Hopkins University has just published the results of a survey of 358 people who reported that psychedelic drugs had helped them quit smoking and 74% had abstained for more than 2 years [19]. Consequently, this team is initiating an RCT of psilocybin-assisted psychotherapy for smoking cessation involving 40 participants [20].Meanwhile, a proof-of-concept study has found that treatment of alcohol dependence with psilocybin-assisted psychotherapy yielded similarly impressive effects [21]. This team at New York University is now undertaking an RCT of 180 people that includes functional magnetic resonance imaging scanning [22]. Second, while it is not considered a prototypical psychedelic, new research is showing that MDMA holds great promise in curing treatment-refractory PTSD [9]. This is significant because many people who develop substance use disorders have a history of psychological trauma [23,24]. Within the Australian Treatment Outcomes Study, 41% of people receiving treatment for heroin dependence met criteria for PTSD [25]. Some have suggested that the rates of trauma among people with substance use disorders may be even higher than first thought. Among a sample of 423 Dutch people with a range of substance use disorders, Gielen et al. [26] found 46.2% whose primary drug of choice was alcohol met the criteria for PTSD. MDMA was used in psychotherapy in the 1970s and early 1980s as a safe adjunct to couples counselling and to address psychological trauma, prior to its emerging popularity as a recreational drug. The first clinical study reporting on the therapeutic effects of MDMA was published in 1986 by Greer and Tolbert [27]. Described accurately as an ‘empathogen’ or ‘entactogen’, the compound has the unique properties of establishing empathy with clinical staff while concurrently creating an emotional openness in the client that allows him or her to reprocess the traumatic event/s within the window of tolerance, without fear or shame [9]. MDMA appears to function as a catalyst for the psychotherapeutic process and is described by Sessa