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Krista J. Siefried

11 papers in the library · 14 citations · publishing 2024-2026

Papers

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Through the Looking-Glass: A Scoping Review of Psychological Mechanisms of Psychedelic-Assisted Therapy for Substance Use Disorders

Current Addiction Reports September 2, 2026 Kathryn Fletcher, Jack Freestone, Nadine Ezard et al.

Abstract Purpose of Review Psychedelic-assisted therapy (PAT) has re-emerged as a potential intervention for substance use disorders (SUDs), yet the psychological mechanisms underlying behaviour change remain poorly synthesised. This scoping review mapped and evaluated proposed psychological processes underpinning PAT in adults with SUDs. Recent Findings Peer-reviewed English-language empirical...

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...

DOI: 10.3389/fpsyt.2026.1873497 (opens in new tab) Thematic analysis Context archaeology Cognition Qualitative research +8

"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...

Exploring the Utility and Appropriateness of Dose Thresholds for Issuing of Public Drug Alerts on High-Dose MDMA: A Qualitative Study.

Drug and Alcohol Review March 1, 2026 Jack Freestone, Harriet MacDonald, Stassi Kypri et al.

Drug alerts are sometimes issued when samples are found to exceed a pre-determined dose threshold. In Australia, it is common for alerts to be issued when MDMA pills contain ≥ 150 mg of MDMA free-base or 179 mg hydrochloride. Nineteen such alerts were issued in Australia in 2024, raising concerns that repeat alerts may lose impact over time. This study examined experts' viewpoints on the...

'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...

DOI: 10.1186/s12954-026-01405-1 (opens in new tab) Full text (opens in new tab) Chemsex Ghb Gamma-hydroxybutyrate Heterosexual +5

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...

DOI: 10.1111/add.70284 (opens in new tab) Qualitative research Qualitative analysis Interpersonal communication Focus group +7

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...

DOI: 10.1136/bmjopen-2024-092504 (opens in new tab) Full text (opens in new tab) Drug therapy Feasibility studies Psychosocial intervention Safety +6

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,...

DOI: 10.3389/fpsyt.2024.1490907 (opens in new tab) Psilocybin Methamphetamine Hallucinogen Psychotherapist +1