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Ben Beaglehole

Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.

6 papers in the library · 41 citations · publishing 2024-2026

Papers

Six weeks open-label oral ketamine for patients with treatment-resistant depression, post-traumatic stress disorder, or obsessive-compulsive disorder.

Journal of psychopharmacology (Oxford, England) June 5, 2025 Ben Beaglehole, Paul Glue, Shona Neehoff et al. 19 citations

In an open-label extension of a prior crossover trial, oral ketamine was given for six weeks to people with treatment-resistant depression, post-traumatic stress disorder, or obsessive-compulsive disorder. Doses started at 1-1.5 mg/kg and increased to 1.5-2.5 mg/kg, taken one to three times per week. Symptom scores remained low throughout the six weeks, and the oral formulation was well tolerated with few side effects. The findings suggest that oral ketamine can sustain improvements in these treatment-resistant conditions and offers a practical alternative for maintenance therapy.

Ketamine for treatment-resistant obsessive-compulsive disorder: Double-blind active-controlled crossover study.

Journal of psychopharmacology (Oxford, England) January 1, 2025 Ben Beaglehole, Paul Glue, Shona Neehoff et al. 12 citations

Ketamine reduces obsessive-compulsive symptoms more than a psychoactive control (fentanyl) in people with severe, treatment-resistant OCD. In a small double-blind trial, participants received a single intramuscular dose of either 0.5 mg/kg ketamine, 1.0 mg/kg ketamine, or 50 µg fentanyl. Both ketamine doses produced greater and dose-related reductions on the Yale-Brown Obsessive-Compulsive Scale, with effects separating from fentanyl within 1–2 hours and persisting for up to 168 hours. Ketamine caused short-term dissociative and cardiovascular effects; two of twelve participants dropped out due to not tolerating dissociation. The findings provide preliminary evidence for ketamine's efficacy and tolerability in an outpatient cohort.

Ketamine for treatment-resistant post-traumatic stress disorder: double-blind active-controlled randomised crossover study

BJPsych Open October 1, 2025 Ben Beaglehole, Paul Glue, Shona Neehoff et al. 5 citations

Intramuscular ketamine shows preliminary effectiveness and is well tolerated by people with posttraumatic stress disorder in a community setting. The findings are encouraging given the known limitations of existing treatments, but more research is needed to determine the best dosing schedule and long-term role of ketamine for PTSD.

Protocol for a randomised controlled trial of ketamine versus ketamine and behavioural activation therapy for adults with treatment-resistant depression in the community.

BMJ open May 1, 2024 Ben Beaglehole, Richard Porter, Katie Douglas et al. 5 citations

A randomized controlled trial will test the feasibility of adding behavioral activation therapy (BAT) to oral ketamine for treatment-resistant major depressive disorder. The study aims to recruit 60 adults aged 18–65 years, randomizing them to eight weeks of oral ketamine with BAT or oral ketamine alone. Feasibility will be measured by attendance, acceptability, and retention. The primary efficacy outcome is the Montgomery-Asberg Depression Rating Scale, assessed weekly during treatment and fortnightly during 12 weeks of follow-up. For a definitive trial to be recommended, the study must meet recruitment targets and show a greater than 20% reduction in relapse rates favoring the combined treatment arm.

Ketamine effects on EEG and their links to therapy differ across treatment-resistant major depression, post-traumatic stress disorder, and obsessive-compulsive disorder

The International Journal of Neuropsychopharmacology July 6, 2026 Shabah M. Shadli, Neda Nasrollahi, Calvin K. Young et al.

Ketamine at low doses (0.5-1.0 mg/kg I.M.) quickly reduces symptoms in treatment-resistant major depressive disorder (TR-MDD), post-traumatic stress disorder (TR-PTSD), and obsessive-compulsive disorder (TR-OCD), but its neural effects differ by diagnosis. EEG recordings of resting frontal activity before and after ketamine or fentanyl showed that TR-PTSD patients had dose- and band-frequency-dependent power changes (especially alpha at 0.5 mg/kg), while TR-MDD patients showed no such changes. TR-OCD responses differed qualitatively from both. Correlations between EEG power changes and symptom scale improvements varied by band and electrode across different disorder-specific scales. Ketamine's effects and their therapeutic links vary by brain site and frequency band depending on the DSM diagnosis, suggesting disorder-specific systems require a ketamine-sensitive factor to generate the disorder.

Reappraisal of the hype and hope offered by psilocybin treatment of depression

New Zealand Medical Journal September 15, 2025 Ben Beaglehole, Jenni Manuel

Psilocybin treatment for depression shows early promise, but expectation bias and functional unblinding likely influence positive results. Side effects are often not systematically reported, and some recipients may experience harm. Compared to ketamine for treatment-resistant depression, the evidence for psilocybin is weaker; ketamine has stronger support in treatment-resistant groups. The authors conclude that current evidence does not justify wider availability or use of psilocybin for depression.