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Allan H Young

King's College London, Institute of Psychiatry, Psychology and Neuroscience, London, UK.

22 papers in the library · 1,530 citations · publishing 2022-2026

Papers

Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression.

The New England journal of medicine November 3, 2022 Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al. 1,095 citations

A single 25 mg dose of psilocybin, but not 10 mg, reduced depression scores more than a 1 mg control dose over three weeks in adults with treatment-resistant depression. In this phase 2 trial, 233 participants were randomly assigned to 25 mg, 10 mg, or 1 mg of synthetic psilocybin with psychological support. The 25 mg group showed an average 12-point drop on the MADRS depression scale versus a 5.4-point drop in the 1 mg group, a significant difference. The 10 mg group did not differ significantly from control. Response and remission rates at three weeks supported the primary result, but sustained response at 12 weeks was not significantly different.

Single-dose psilocybin for a treatment-resistant episode of major depression: Impact on patient-reported depression severity, anxiety, function, and quality of life

Journal of Affective Disorders February 3, 2023 Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al. 168 citations

Three weeks after a single dose, 25 mg of psilocybin, and to a lesser extent 10 mg, improved patient-reported measures of depression severity, anxiety, affect, and functioning in people with treatment-resistant depression. These findings extend the primary results from the largest randomized clinical trial of psilocybin for TRD, highlighting outcomes that matter to patients.

The role of the psychedelic experience in psilocybin treatment for treatment-resistant depression.

Journal of affective disorders March 1, 2025 Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al. 35 citations

In treatment-resistant depression, a single dose of 25 mg of psilocybin produced stronger correlations between certain psychedelic experiences and depression improvement three weeks later than lower doses. The intensity of psychedelic effects was dose-related, but scores for different doses overlapped considerably. At the 25 mg dose, dimensions of oceanic boundlessness and visual restructuralization, along with emotional breakthrough, showed the strongest correlations with reduced depression scores. The study does not establish causation and requires replication. The overlap in experience intensity across doses suggests unblinding to dose is less likely. Correlations between psychedelic experience and outcome indicate specificity in psilocybin's mechanism of action.

Safety and efficacy with esketamine in treatment-resistant depression: long-term extension study.

The international journal of neuropsychopharmacology June 6, 2025 Naim Zaki, Li Nancy Chen, Rosanne Lane et al. 32 citations

In a long-term extension study (SUSTAIN-3) involving 1,148 adults with treatment-resistant depression, esketamine nasal spray combined with an oral antidepressant was evaluated for safety and efficacy over up to 79 months (median 45.8 months). Common adverse events included headache (36.9%), dizziness (33.9%), and nausea (33.6%). Nine participants died, with causes including COVID-19 and suicide. Depressive symptoms, measured by the MADRS, improved during the initial induction phase (average reduction of 12.8 points) and this improvement was maintained during the optimization/maintenance phase. At the end of maintenance, 49.6% of participants were in remission. No new safety concerns emerged, and depression improvement generally persisted for those continuing treatment.

Phase 1, placebo-controlled, single ascending dose trial to evaluate the safety, pharmacokinetics and effect on altered states of consciousness of intranasal BPL-003 (5-methoxy-N,N-dimethyltryptamine benzoate) in healthy participants.

Journal of psychopharmacology (Oxford, England) August 1, 2024 James Jonathan Rucker, Claire Roberts, Mathieu Seynaeve et al. 32 citations

A new intranasal formulation of 5-MeO-DMT, called BPL-003, was tested in 44 healthy people who had never used psychedelics. Doses up to 12 mg were well tolerated, with no serious side effects; common mild effects included nasal discomfort, nausea, headache, and vomiting. The drug was absorbed quickly, reaching peak levels in about 8–10 minutes, and cleared from the body in under 27 minutes. Higher doses produced stronger subjective drug intensity and mystical experiences, with 60% of participants reporting a 'complete mystical experience' at 10 and 12 mg. The rapid onset and short duration suggest potential for treating conditions like depression.

Safety and tolerability of esketamine nasal spray versus quetiapine extended release in patients with treatment resistant depression.

European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology August 1, 2024 Roger S McIntyre, Istvan Bitter, Jozefien Buyze et al. 30 citations

In the ESCAPE-TRD trial, esketamine nasal spray caused treatment-emergent adverse events more often than quetiapine extended release (91.9% versus 78.0%), but these events were typically mild or moderate and transient: 92.0% resolved the same day, and only 4.2% of patients discontinued esketamine due to adverse events compared with 11.0% for quetiapine. The median proportion of days with adverse events was lower with esketamine (11.9% versus 21.3%). Along with greater efficacy, esketamine's tolerability profile supports its use for treatment-resistant depression.

Effect of naltrexone pretreatment on ketamine-induced glutamatergic activity and symptoms of depression: a randomized crossover study.

Nature medicine July 24, 2025 Luke A Jelen, David J Lythgoe, James M Stone et al. 29 citations

Blocking the opioid system with naltrexone reduced both the brain glutamate response and the antidepressant effect of ketamine in adults with major depressive disorder. In a double-blind crossover study of 26 adults, naltrexone before ketamine infusion attenuated the rise in glutamate+glutamine relative to N-acetylaspartate in the anterior cingulate cortex and lessened the drop in depression scores the next day. The opioid system modulates ketamine's acute brain effects and subsequent mood improvement, suggesting interactions between glutamate and opioid systems may inform new depression treatments.

Psychedelics for treatment resistant depression: are they game changers?

Expert Opinion on Pharmacotherapy November 10, 2023 Michail Kalfas, Rosie H Taylor, Dimosthenis Tsapekos et al. 28 citations

Psychedelic therapy is transforming treatment for treatment-resistant depression (TRD) by increasing benefits and reducing risks. Psilocybin shows promise as a potential game-changer, with initial evidence indicating a rapid antidepressant effect that lasts at least three months for some responders. However, more rigorous, double-blind, comparator-controlled trials with adequate statistical power are needed to understand how psychedelics work and their long-term effects in TRD. Psychedelics may also benefit other psychiatric conditions like bipolar depression and post-traumatic stress disorder.

Is it now time to prepare psychiatry for a psychedelic future?

The British Journal of Psychiatry May 20, 2024 David Nutt, Ilana Crome, Allan H Young 18 citations

Australia has reclassified psilocybin and MDMA from prohibited substances to prescription medicines for treatment-resistant depression and post-traumatic stress disorder, respectively. The feature examines the rationale behind these regulatory changes, the potential benefits and difficulties they present to psychiatric practice, and how mental health professionals and healthcare systems can adapt to integrate these treatments.

Ketamine cystitis following ketamine therapy for treatment-resistant depression – case report

BMC Psychiatry January 2, 2024 Minna Chang, Mario F Juruena, Allan H Young 16 citations

Ketamine, a promising antidepressant for treatment-resistant depression, can cause ulcerative cystitis—a bladder condition with lower urinary tract symptoms and potential kidney damage seen in over 25% of regular recreational users. This condition, known as ketamine-induced cystitis (KIC), had not been reported in therapeutic use until now. A 28-year-old woman developed KIC symptoms after starting ketamine for depression, confirmed by urine tests. Early diagnosis and stopping ketamine can improve symptoms and prevent further harm. This is the first reported case of KIC in a patient receiving treatment-dose ketamine for depression.

Early Clinical Experiences of Esketamine Nasal Spray in the UK in Adults with Treatment-Resistant Major Depressive Disorder: Advisory Panel Recommendations.

Neuropsychiatric disease and treatment January 1, 2023 Allan H Young, Mohamed Abdelghani, Mario F Juruena et al. 10 citations

Treatment-resistant depression (TRD) imposes severe burdens on patients, health services, and society, yet has lacked viable treatment options. An advisory panel of psychiatrists and clinical researchers experienced in managing TRD developed best practice statements on using esketamine nasal spray, one of the first TRD treatments licensed in 30 years. The panel agreed on recommendations for setting up and running an efficient esketamine clinic, emphasizing logistical planning, patient education to prevent discontinuation, and checklists for safe appointments. Expanding treatment options like esketamine nasal spray is likely key to improving long-term outcomes for this underserved population.

Mindfulness-based cognitive therapy versus treatment as usual after non-remission with NHS Talking Therapies high-intensity psychological therapy for depression: a UK-based clinical effectiveness and cost-effectiveness randomised, controlled, superiority trial.

The lancet. Psychiatry June 1, 2025 Thorsten Barnhofer, Barnaby D Dunn, Clara Strauss et al. 9 citations

About half of patients with depression who complete the UK National Health Service Talking Therapies stepped care pathway still have symptoms. A randomized trial tested whether adding mindfulness-based cognitive therapy (MBCT) via videoconference to treatment as usual improves outcomes for these patients. At 34 weeks, the MBCT group had significantly lower depression scores than the treatment-as-usual group (adjusted difference -2.49 points on the PHQ-9). The MBCT group also had slightly lower healthcare costs and higher quality-of-life scores, with a 99% chance of being cost-effective at the £20,000 per QALY threshold. No serious adverse events occurred. MBCT is an effective and scalable further-line treatment for depression that does not remit after psychological therapy.

Efficacy of esketamine nasal spray over quetiapine extended release over the short and long term: sensitivity analyses of ESCAPE-TRD, a randomised phase IIIb clinical trial.

The British journal of psychiatry : the journal of mental science February 1, 2025 Allan H Young, Pierre-Michel Llorca, Andrea Fagiolini et al. 7 citations

In people with treatment-resistant depression, esketamine nasal spray outperformed quetiapine extended release across multiple measures. Sensitivity analyses using different definitions of remission and relapse consistently favored esketamine, with relative risks for the primary endpoint ranging from 1.462 to 1.737 and for the key secondary endpoint from 1.417 to 1.838. Esketamine also shortened time to first remission by 71% and confirmed remission by 66%. The robustness of the original ESCAPE-TRD trial findings was confirmed.

Guidelines for ketamine use in clinical psychiatry practice.

BJPsych open May 10, 2024 Luke A Jelen, Rupert McShane, Allan H Young 7 citations

Ketamine shows promise for treatment-resistant depression, but its use requires careful management through evidence-based guidelines. The editorial emphasizes the need for comprehensive protocols to oversee both licensed and off-licence ketamine formulations, referencing recent efforts to develop such guidelines in New Zealand. It advocates for national registries to monitor ketamine therapy, ensuring responsible and effective treatment for depression.

Urological symptoms following ketamine treatment for psychiatric disorders: A systematic review.

Journal of psychopharmacology (Oxford, England) June 30, 2025 Jess Kerr-Gaffney, Anna Tröger, Alice Caulfield et al. 6 citations

Ketamine, a rapid-acting treatment for depression and other psychiatric conditions, has raised safety concerns because chronic recreational use can damage the bladder and urinary tract. This systematic review of 27 clinical studies, mostly in people with depression, found that 0% to 24.5% of patients receiving ketamine reported urological symptoms, which were usually mild or moderate. Objective measures of bladder and kidney function showed no significant changes from before to after treatment. The evidence suggests that therapeutic ketamine does not appear to increase the risk of urological problems, but most studies were short-term and did not systematically monitor symptoms, so more long-term research is needed.

A randomized, double-blind, placebo-controlled, Phase 1 study to investigate the safety, tolerability, pharmacokinetics and pharmacodynamics of an immediate-release oral ketamine capsule in healthy volunteers.

Journal of psychopharmacology (Oxford, England) June 20, 2025 Mutahira Qureshi, Daniel Silman, Romayne Gadelrab et al. 3 citations

A single dose of immediate-release oral ketamine (40–240 mg) was safe and generally well-tolerated in healthy adults, with no unexpected safety signals or discontinuations due to side effects. Eighty mild or moderate treatment-emergent adverse events occurred after ketamine doses, most commonly dissociation, dizziness, and headache, while only five occurred after placebo. Dissociation events increased with higher doses. Ketamine and its metabolites showed dose-proportional pharmacokinetics. Transient mood and dissociation changes appeared one hour after dosing and resolved within about four hours. These results support further investigation of oral ketamine capsules for treatment-resistant depression.

The role of therapeutic alliance in psilocybin treatment for treatment-resistant depression: A post hoc path analysis.

Journal of affective disorders August 1, 2026 Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al. 2 citations

In people with treatment-resistant depression receiving 25 mg psilocybin with monitoring and support, the therapeutic alliance before dosing had only weak correlations with improvement in depression scores at three weeks. Stronger correlations were seen with the intensity of the psychedelic experience itself, particularly emotional breakthrough and visual restructuring. Path analysis suggested that therapeutic alliance helped facilitate the psychedelic experience, but it was the psychedelic experience—not the alliance—that had stronger direct effects on clinical outcomes. The alliance's direct effect on antidepressant response was limited or absent.

Regional Blood Flow Signatures of Opioidergic Modulation of Ketamine in Major Depressive Disorder: A Randomized Crossover Study.

The American journal of psychiatry June 1, 2026 Luke A Jelen, Owen O'Daly, Fernando O Zelaya et al. 2 citations

Ketamine increased blood flow in specific brain regions (subgenual, pregenual, and dorsal anterior cingulate cortices) in adults with major depressive disorder, and this effect was not blocked by the opioid blocker naltrexone. However, naltrexone did disrupt the relationships between blood flow changes and both acute subjective effects and antidepressant response. The blood flow changes aligned with patterns of opioid and glutamate receptor distribution, suggesting that ketamine's effects involve interactions among multiple neurotransmitter systems.

A systematic review of the pharmacokinetics of classical serotonergic psychedelic compounds in healthy adult subjects.

Journal of psychopharmacology (Oxford, England) May 29, 2026 Elliot Hampsey, Kirsty Martin, Michail Kalfas et al.

A systematic review of 32 trials in healthy adults found that LSD and psilocybin show dose-proportional peak concentrations (Cmax), while DMT's oral and intravenous formulations differ in ways that may be clinically significant. LSD was the most studied psychedelic, followed by DMT and psilocybin; mescaline appeared in only two trials. Single studies examined intravenous LSD, intravenous psilocybin, inhaled 5-MEO-DMT, and intranasal 5-MEO-DMT. Variations in absorption, distribution, and elimination among the compounds may have important implications for clinical and research settings.

Global Perspectives on CNS Drug Innovation: Achievements, Barriers, and Priorities for the Next Decade

The International Journal of Neuropsychopharmacology May 5, 2026 Hiroyuki Uchida, Gabriella Gobbi, Joseph Zohar et al.

Between 2013 and 2026, neuropsychopharmacology advanced from stagnation to momentum, producing several first-in-class treatments: rapid-acting drugs for treatment-resistant depression (intranasal esketamine), psychedelic-assisted therapy for PTSD and depression, neuroactive steroid GABA-A receptor positive allosteric modulators (brexanolone, zuranolone) for postpartum depression, non-dopaminergic muscarinic agonists (xanomeline-trospium) for schizophrenia, orexin receptor antagonists for insomnia, and anti-amyloid monoclonal antibodies (lecanemab, donanemab) for early Alzheimer's disease.

Comparison of average time-to-relapse following ECT versus ketamine - A systematic review.

Journal of psychopharmacology (Oxford, England) April 16, 2026 Minna Chang, Allan H Young, Mario F Juruena

Both electroconvulsive therapy (ECT) and ketamine show sustained therapeutic potential for treatment-resistant depression, with ECT possibly associated with longer remission. Higher doses, more frequent administration, and maintenance ECT or ketamine appear to prolong remission, and continuing oral antidepressants may extend it further. This systematic review of 13 studies found no direct head-to-head comparisons of time-to-relapse between the two treatments that met inclusion criteria, preventing formal statistical analysis. The review excluded studies involving psychotic depression, limiting generalizability to those populations.