Skip to content

Jonathan Brett

14 papers in the library · 65 citations · publishing 2023-2026

Papers

Sort Most recent Most cited

Editorial: Emerging treatment approaches for substance use disorders

Frontiers in Psychiatry July 21, 2026 David Martinez Garza, Ilya O. Blokhin, Jonathan Brett et al.

Since the introduction of disulfiram in 1951 (the first ever Food and Drug Administration (FDA)-approved medication for substance use disorders (SUDs)) (1), only seven other individual medications have been approved for the treatment of SUDs. While the repurpose of medications and different formulations increase the total number of FDA-approved medicines (Table 1 and(2)), the arsenal of...

Navigating ‘k-land’: a qualitative exploration of participants’ experiences of ketamine-assisted psychotherapy for methamphetamine use disorder

Frontiers in Psychiatry June 24, 2026 Kathryn Fletcher, Nadine Ezard, Krista J. Siefried et al.

Background Methamphetamine use disorder (MAUD) is associated with substantial psychiatric and physical morbidity, and current treatment options remain limited. Ketamine-assisted psychotherapy (KAP) has shown promise in substance use disorders, but little is known about how individuals experience and interpret this intervention, particularly in MAUD. Qualitative investigation may provide insight...

"Large-Scale and Local Functional Connectivity Changes Following Psilocybin Administration in Methamphetamine Use Disorder.

AJNR. American journal of neuroradiology April 24, 2026 Joga Chaganti, Krista J. Siefried, Veda S Vyakaranam et al.

Methamphetamine (MA) use disorder is associated with widespread disruption of large-scale brain networks involved in cognitive control, attention, and salience processing. Resting-state functional MRI (rs-fMRI) provides a means to characterize these alterations; however, little is known about the capacity for functional network reorganization following targeted intervention. The purpose of this...

'A fine line between euphoria and death': a qualitative study exploring gamma-hydroxybutyrate (GHB) use among people who identify as heterosexual living in Australia.

Harm Reduction Journal February 6, 2026 Keaton Hudson-Buhagiar, Jonathan Brett, Alanah Spillane et al. 1 citation

Harms associated with gamma-hydroxybutyrate (GHB) use have increased recently in Australia. However, research predominantly focuses on the experience of GHB use among LGBTQ + populations. Non-prescribed GHB use has not been well described in heterosexual populations. Research to examine the experience of heterosexual people, including motivations for use, experiences of harms, and utilisation...

A qualitative analysis of participant expectations and experiences of psilocybin‐assisted psychotherapy for methamphetamine use disorder

Addiction December 22, 2025 Jonathan Brett, Toby Lea, Elizabeth Knock et al.

Abstract Background and aims There is an urgent unmet need for novel treatments for methamphetamine (MA) use disorder. We explored the qualitative experiences of people participating in a study of psilocybin‐assisted psychotherapy (PAT) to treat MA use disorder. Design and setting Qualitative study of participants enrolled in a single arm, open‐label pilot study of PAT for MA use disorder...

Psilocybin‐assisted psychotherapy for methamphetamine use disorder: A pilot open‐label safety and feasibility study

Addiction September 20, 2025 Elizabeth Knock, Krista J. Siefried, Gillinder Bedi et al. 4 citations

Abstract Background & Aims There are few effective treatments for methamphetamine use disorder, despite increasing global demand. Here, we assessed the safety and feasibility of outpatient psilocybin‐assisted psychotherapy for methamphetamine use disorder. Design Single arm, open label pilot study. Setting Outpatient public stimulant treatment program at St. Vincent's Hospital, Sydney,...

Exploring psychedelic experiences among people who regularly use methamphetamine: Findings from an international survey.

Drug and Alcohol Dependence July 1, 2025 Dilara Bahceci, Krista J. Siefried, Maureen Steele et al.

Methamphetamine use disorder, associated with significant morbidity and mortality, has limited effective treatments. Psychedelic-assisted psychotherapy shows promise, but data on its safety and efficacy in this population are limited. This exploratory study describes the demographic, substance use, and mental health characteristics of people who used methamphetamine and psychedelics and the...

Exploring the perceived usefulness of integration support after naturalistic psychedelic experiences in people concerned about their substance use: A survey

Journal of Psychedelic Studies April 22, 2025 Sophie van der Helder, Krista J. Siefried, Liam Acheson et al. 1 citation

Improved outcomes for substance use disorders have been described following non-clinical (“naturalistic”) psychedelic use. This exploratory study aimed to describe the naturalistic psychedelic experiences of people with substance use concerns and their reported needs and perceived utility of psychosocial support following naturalistic psychedelic use to integrate experiences and achieve...

Protocol of an open-label safety and feasibility pilot study of ketamine-assisted psychotherapy for methamphetamine use disorder (the KAPPA trial).

BMJ Open February 10, 2025 Kathryn Fletcher, Nadine Ezard, Krista J. Siefried et al. 1 citation

Methamphetamine use disorder is a significant public health concern. No pharmacological treatment options currently exist for methamphetamine use disorder, and psychotherapy is only moderately effective. Preliminary evidence suggests that ketamine-assisted psychotherapy produces sustained improvements in substance use and mental health symptomatology. In addition to direct antidepressant...

Psilocybin-assisted psychotherapy for methamphetamine dependence: a case report involving daily methamphetamine use

Frontiers in Psychiatry December 6, 2024 Jonathan Brett, Elizabeth Knock, Kathy Watson et al. 7 citations

Methamphetamine (MA) dependence leads to severe physical and psychological issues. Current treatments, including psychosocial therapies and residential rehabilitation, face limitations such as high relapse rates, cost, and accessibility issues. As a result, there is an urgent need for novel approaches to treat MA dependence that are effective, affordable, and accessible to patients. Psilocybin,...

Drug dependence and prescribing ketamine for treatment-resistant depression in Australia and New Zealand.

The Australian and New Zealand journal of psychiatry October 1, 2024 Alistair Carroll, Adam Bayes, Mark Montebello et al. 10 citations

Ketamine is a restricted and regulated medication in Australia and New Zealand, which has implications when considering treatment for patients with treatment-resistant depression and a history of illicit drug use, abuse or dependence. Regulations governing prescription of ketamine for treatment-resistant depression vary between jurisdictions in Australia and New Zealand, though most restrict...

The psychedelic call: analysis of Australian Poisons Information Centre calls associated with classic psychedelics.

Clinical toxicology (Philadelphia, Pa.) April 1, 2024 Rachael Wilkes, Darren M Roberts, Paul Liknaitzky et al. 8 citations

The global use of certain classical psychedelics has increased in recent years, but little is known about their spectrum of toxicity within Australia. We aim to describe calls to New South Wales Poisons Information Centre relating to exposures to classical psychedelics including lysergic acid diethylamide, psilocybin, N,N-dimethyltryptamine, ayahuasca, mescaline and ibogaine. This is a...

Who are you after psychedelics? A systematic review and a meta-analysis of the magnitude of long-term effects of serotonergic psychedelics on cognition/creativity, emotional processing and personality

Neuroscience & Biobehavioral Reviews February 3, 2024 Ivana Solaja, Kate Haldane, Natasha L. Mason et al. 17 citations

This systematic review and a meta-analysis synthesised the results from contemporary, randomized and non-randomized controlled studies to assess lasting (one week minimum) changes on cognition/creativity, emotional processing and personality from serotonergic psychedelics. PubMed, Embase and PsycInfo were searched in July 2022. Risk of bias was assessed using Rob 2.0 and ROBINS-I. Ten studies...

Exploring psilocybin-assisted psychotherapy in the treatment of methamphetamine use disorder

Frontiers in Psychiatry March 14, 2023 Jonathan Brett, Elizabeth Knock, Paul Liknaitzky et al. 16 citations

Methamphetamine use disorder is a chronic relapsing condition associated with substantial mental, physical, and social harms and increasing rates of mortality. Contingency management and psychotherapy interventions are the mainstays of treatment but are modestly effective with high relapse rates, while pharmacological treatments have shown little to no efficacy. Psilocybin-assisted...