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Theis H Terwey

GH Research, Dublin, Ireland.

4 papers in the library · 146 citations · publishing 2021-2026

Papers

A phase 1/2 trial to assess safety and efficacy of a vaporized 5-methoxy-N,N-dimethyltryptamine formulation (GH001) in patients with treatment-resistant depression

Frontiers in Psychiatry June 20, 2023 Johannes T Reckweg, Cees J van Leeuwen, Cécile Henquet et al. 86 citations

In a small clinical trial with 16 adults suffering from treatment-resistant depression, an inhaled form of the psychedelic drug 5-MeO-DMT (GH001) was well tolerated and produced rapid antidepressant effects. An individualized dosing regimen of up to three increasing doses within a single day led to 87.5% of patients achieving remission (a depression score of 10 or less on the MADRS scale) by day 7, compared to 50% and 25% for single doses of 12 mg and 18 mg, respectively. Remission occurred as early as two hours after dosing for some patients. The findings suggest that individualized dosing may be more effective than a single dose.

A Phase 1, Dose-Ranging Study to Assess Safety and Psychoactive Effects of a Vaporized 5-Methoxy-N, N-Dimethyltryptamine Formulation (GH001) in Healthy Volunteers.

Frontiers in pharmacology January 1, 2021 Johannes Reckweg, Natasha L Mason, Cees Van Leeuwen et al. 58 citations

Vaporized 5-MeO-DMT (GH001) produces dose-dependent increases in psychedelic experience intensity in healthy volunteers, with individualized dose escalation yielding maximal effects on peak experience, mystical experience, ego dissolution, and altered states of consciousness. Higher single doses (6, 12, 18 mg) significantly increased ratings compared to 2 mg on all measures except challenging experiences. Cognition, mood, and well-being were unaffected. Vital signs remained stable, and adverse events were mild and self-resolving. Individualized dose escalation may be preferable for clinical applications aiming to maximize the psychedelic experience for therapeutic response.

Evaluation of the peak experience scale as a rapid assessment tool for the strength of a psychoactive experience with 5-MeO-DMT.

Frontiers in psychology January 1, 2025 Johannes T Reckweg, Natasha L Mason, Eef L Theunissen et al. 2 citations

A three-item Peak Experience Scale (PES) was developed to quickly gauge the intensity of the psychoactive experience with the psychedelic 5-MeO-DMT and to guide dosing. Data came from three studies involving 84 healthy volunteers and patients with treatment-resistant depression who inhaled a 5-MeO-DMT formulation at doses of 0 (placebo), 2, 6, 12, or 18 mg, or an incremental individualized dosing regimen. PES ratings increased significantly with dose, peaking after the individualized regimen. The scale showed strong internal consistency and high correlation with other psychedelic assessment tools like the Mystical Experience Questionnaire and Ego Dissolution Inventory, but not with the Challenging Experience Questionnaire. The PES is an effective, simple tool for rapidly assessing psychedelic experience strength and may help guide dosing of rapid-acting psychedelics.

Inhaled Mebufotenin (GH001) for Adult Patients With Postpartum Depression: A Phase 2a Open-Label Clinical Trial.

The Journal of clinical psychiatry June 3, 2026 Martin Johnson, Pau Aceves Baldo, Emilio Arbe et al.

In a small open-label trial, ten women with postpartum depression received up to three escalating doses of inhaled GH001 (a synthetic form of 5-MeO-DMT) on a single day. Depressive symptoms, measured on the Montgomery-Asberg Depression Rating Scale, dropped by an average of 35.4 points from a baseline of 36.7 by day 8, and all participants met criteria for both response and remission. Improvements were first noted two hours after the final dose. The treatment was well tolerated, with only mild to moderate side effects, most commonly headache. These preliminary findings suggest GH001 may produce rapid and substantial antidepressant effects in postpartum depression, but larger controlled trials are needed.