Psychedelic medicine (New Rochelle, N.Y.)
June 1, 2024
Ryan Yermus, John Bottos, Nathan Bryson et al.
13 citations
Ketamine-assisted psychotherapy (KAP) produces sustained reductions in anxiety, depression, and PTSD symptoms lasting up to 5 months after the last session. In a retrospective study of adults with treatment-resistant major depressive disorder, generalized anxiety disorder, or PTSD who received KAP across 11 North American clinics, large treatment effects were detected at 3 months (Cohen's d = 0.75-0.86) and sustained at 6 months (d = 0.61-0.73). Case reductions ranged from 39% to 41% at 3 months and 29% to 37% at 6 months. However, high attrition rates (82% at 3 months, 95% at 6 months) may limit validity of the results.
ACS Chemical Neuroscience
May 17, 2024
Nathan Bryson, Robert Alexander, Aviva Asnis-Alibozek et al.
9 citations
A prodrug called RE104, which releases the short-acting psychedelic 4-OH-DiPT (structurally similar to psilocin), was characterized in rats. 4-OH-DiPT is a synthetic serotonin 2A receptor agonist with a reported 2-3 hour duration of psychedelic effects, shorter than psilocybin. RE104 incorporates a glutarate moiety that cleaves rapidly in the body to provide the active drug. In rats, plasma concentrations of 4-OH-DiPT correlated with head-twitch intensity, and its half-life was 40 minutes after subcutaneous RE104 administration. A single 1 mg/kg dose of RE104 significantly reduced immobility time in the forced swim test one week later, indicating potential antidepressant activity.
Journal of clinical psychopharmacology
July 21, 2025
Guy Ludbrook, Nathan Bryson, Beatrix Taylor et al.
2 citations
A single subcutaneous dose of RE104, a prodrug of the synthetic psychedelic 4-OH-DiPT, was generally safe and well-tolerated in 48 healthy adults with prior psychedelic experience. Doses from 5 to 40 mg produced no serious adverse events or deaths; most side effects were mild to moderate and occurred under supervision. The drug appeared rapidly in the blood, with peak levels reached in 1.0 to 1.25 hours and a half-life of 2.72 to 4.12 hours. Exposure increased proportionally with dose. Plasma levels correlated with drug effects and mystical experiences, and higher doses produced more complete mystical experiences. The psychoactive experience lasted 3 to 4 hours, shorter than psilocybin, suggesting a favorable therapeutic profile.
medRxiv
January 17, 2023
Ryan Yermus, Michael Verbora, Sidney H. Kennedy et al.
2 citations
preprint
Ketamine-Assisted Psychotherapy (KAP) produced large and sustained reductions in depression, anxiety, and PTSD symptoms for up to six months after treatment. In a retrospective trial of 1806 adults with treatment-resistant depression, anxiety, or PTSD, effect sizes at three months ranged from 0.75 to 0.86 and were maintained at six months (0.61 to 0.73). Between 39% and 41% of patients showed case reductions at three months, and 29% to 37% at six months. A minimal clinically important difference was reported by 50% to 75% at three months and 48% to 70% at six months. The treatment involved 4 to 6 guided ketamine sessions with psychotherapy.