Skip to content

Anya Ragnhildstveit

10 papers in the library · 84 citations · publishing 2021-2026

Papers

The potential of ketamine for posttraumatic stress disorder: a review of clinical evidence.

Therapeutic advances in psychopharmacology January 1, 2023 Anya Ragnhildstveit, Jeremy Roscoe, Lisa C Bass et al. 49 citations

PTSD has few effective pharmacological treatments, and trauma-focused psychotherapies are limited by provider shortages and low patient engagement, often leading to chronic illness and reduced quality of life. Ketamine, an NMDA receptor antagonist already indicated for major depression with rapid antidepressant effects, shows transdiagnostic potential. A synthesis of clinical evidence—including case reports, chart reviews, open-label studies, and randomized trials—reveals high heterogeneity in presentation and treatment approach but encouraging signals of safety, efficacy, and durability. Future research directions are discussed.

5-MeO-DMT for post-traumatic stress disorder: a real-world longitudinal case study

Frontiers in Psychiatry November 23, 2023 Anya Ragnhildstveit, Ryan Khan, Paul Seli et al. 17 citations

A single dose of vaporized bufotoxin from the Sonoran Desert Toad, containing an estimated 10-15 mg of 5-MeO-DMT, produced clinically significant improvements in chronic, treatment-resistant PTSD in a 23-year-old female. Next-day effects included marked reductions in hopelessness and suicide risk, with improvements sustained at 1-, 3-, 6-, and 12-month follow-ups. The subject reported a complete mystical experience, which may underlie the therapeutic activity. No serious adverse events occurred, but acute nausea, overwhelming subjective effects, and late-onset night terrors were reported. Results suggest 5-MeO-DMT is generally tolerable and effective for PTSD, though the findings are non-generalizable and rely on methods not clinically accepted.

Cannabis-assisted psychotherapy for complex dissociative posttraumatic stress disorder: A case report

Frontiers in Psychiatry February 9, 2023 Anya Ragnhildstveit, Miriam Kaiyo, Matthew Brian Snyder et al. 10 citations

A 28-year-old woman with complex dissociative posttraumatic stress disorder (D-PTSD) underwent ten sessions of cannabis-assisted psychotherapy (CAP) over five months, combined with cognitive behavioral therapy. After treatment, her pathological dissociation score, measured by the Multidimensional Inventory of Dissociation, dropped by 98.5%, and she no longer met criteria for D-PTSD. She also experienced reduced cognitive distractibility, less emotional suffering, and improved psychosocial functioning. The patient has maintained these gains for over two years. The authors suggest CAP, which produced subjective effects similar to psychedelics like psilocybin and ketamine, warrants further research as a potential treatment for D-PTSD.

Registered clinical trials investigating ketamine and esketamine for treatment-resistant depression: A systematic review

Journal of Psychedelic Studies January 16, 2023 M. Brendle, Anya Ragnhildstveit, M. Slayton et al. 7 citations

A review of 56 registered clinical trials on ketamine and esketamine for treatment-resistant depression found that research activity increased since 2008, with peaks in 2015 and 2021. Most trials were Phase 2 or 3, examining these drugs as individual or combination treatments. The Montgomery-Asberg Depression Rating Scale was the most common outcome measure. While large-scale, late-phase trials of esketamine are growing, many trials fail to assess patient characteristics like age, sex, and race that may affect treatment response. Understanding these design gaps can help scientists and funding bodies prioritize high-quality research.

Microdosing psilocybin for major depressive disorder: study protocol for a phase II double-blind placebo-controlled randomised partial crossover trial

BJPsych Open February 16, 2026 Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al. 1 citation

This is a protocol for a phase II trial testing whether very low doses of psilocybin (2 mg, a microdose) can safely and effectively treat major depressive disorder. Forty adults with MDD will receive either psilocybin or a placebo once weekly for four weeks, then all will receive psilocybin for another four weeks. The trial will measure changes in depression symptoms, mood, well-being, attention, creativity, mindfulness, and pro-sociality. Results will be published regardless of outcome. The findings are expected to guide future research on dose regimens, effect sizes, and the role of expectancy bias, and to inform debates about sub-threshold versus threshold doses of psilocybin.

Psilocybin-Assisted Therapy for Adolescent Anorexia Nervosa: Clinical Considerations and Emerging Models of Care.

Current psychiatry reports May 14, 2026 Jamarie A Geller, Rachel Pacilio, Amanda E Downey et al.

Psilocybin-assisted therapy may hold promise for anorexia nervosa, a serious and often treatment-resistant illness. Although research has focused on adults, anorexia frequently begins in adolescence, and early onset is linked to more severe illness, greater psychiatric comorbidity, and more life difficulties. The authors argue that exploring the theoretical potential of this therapy for adolescents is warranted, considering biological implications, developmental stage, and consent. They propose adaptations to adult treatment models and discuss emerging models that address the unique challenges of adolescent patients.

Microdosing psilocybin for major depressive disorder: study protocol for a phase II double-blind placebo-controlled randomised partial crossover trial - CORRIGENDUM.

BJPsych Open May 13, 2026 Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al.

This is a correction notice for a previously published study protocol. The original protocol describes a phase II double-blind placebo-controlled randomised partial crossover trial investigating microdosing psilocybin for major depressive disorder. No new findings or data are presented.

Microdosing Psilocybin for Major Depressive Disorder: Study Protocol for a Phase II Double-Blind Placebo-Controlled Randomized Partial Crossover Trial

November 16, 2025 Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al. preprint

A phase II trial will test whether microdosing psilocybin (2 mg weekly) outperforms placebo for major depressive disorder. Forty adults will receive either psilocybin or placebo for four weeks, then all will receive psilocybin for another four weeks. Depression symptoms and other measures will be assessed at baseline, after four weeks, and after eight weeks, with follow-ups for two years. The study aims to clarify whether microdosing has genuine antidepressant effects or whether benefits are due to expectancy, and to inform future dose regimens and the therapeutic role of sub-threshold versus threshold doses.

Ketamine as a Novel Psychopharmacotherapy for Eating Disorders: Evidence and Future Directions.

Brain sciences March 12, 2022 Anya Ragnhildstveit, Matthew Slayton, Laura Kate Jackson et al.

Eating disorders are serious psychiatric conditions with limited treatment options. Ketamine, a drug approved for treatment-resistant depression, is now being investigated for eating disorders. This review examines the evidence for ketamine in treating anorexia nervosa, bulimia nervosa, and binge eating disorder. Results are encouraging but limited to case reports on anorexia nervosa. More research is needed to determine ketamine's effectiveness across different eating disorder types, establish safety, and optimize dosing.

Case Report: Unexpected Remission From Extreme and Enduring Bulimia Nervosa With Repeated Ketamine Assisted Psychotherapy.

Frontiers in psychiatry January 1, 2021 Anya Ragnhildstveit, Laura Kate Jackson, Sarah Cunningham et al.

Repeated sessions of ketamine assisted psychotherapy (KAP) led to complete and sustained remission in a 21-year-old woman with extreme and enduring bulimia nervosa, a rare outcome for such severe cases. The patient had 40 binge-eating and purging episodes per day that had not responded to prior pharmacological and behavioral treatments. She underwent three courses of KAP over 3 months, each with six sessions twice weekly. Binge-eating and purging reduced dramatically after the first course, with complete cessation of symptoms achieved 3 months post-treatment, and remission sustained for over 1 year. This first report suggests repeated KAP is a promising intervention for bulimia nervosa.