Scientific Reports
July 19, 2023
Adelaida Castillo, Julien Dubois, Ryan M. Field et al.
19 citations
Ketamine administration in healthy participants caused an altered state of consciousness and changes in systemic physiology, including increased pulse rate and electrodermal activity. The drug led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations and decreased global brain connectivity in the prefrontal region. Preliminary evidence suggests that a combination of neural and physiological metrics may predict subjective mystical experiences and reductions in depressive symptoms. The study demonstrates the successful use of fNIRS neuroimaging to measure physiological effects of ketamine in a clinical setting, representing a step toward larger clinical fNIRS studies of psychedelics.
The American Journal on Addictions
April 1, 2015
Cole Marta, Wesley C Ryan, Alex Kopelowicz et al.
17 citations
Ibogaine, a naturally occurring hallucinogen used illegally for addiction treatment, can trigger manic episodes even in people with no prior bipolar diagnosis. This case series reports three patients who developed mania after using unregulated ibogaine—two for self-treating addictions and one for psycho-spiritual purposes. No previous reports of ibogaine-induced mania exist in the literature. Clinicians encountering new-onset mania should inquire about substance use, especially ibogaine, given its growing popularity among vulnerable populations seeking addiction treatment. The authors advise discussing the lack of safety and efficacy data with patients considering ibogaine.
International Journal of Transpersonal Studies
July 1, 2014
Wesley C Ryan, Cole Marta, Ralph J. Koek
5 citations
Intravenous ketamine is a fast-acting treatment for treatment-resistant depression in both unipolar and bipolar forms. Its benefits last days, longer in unipolar depression, and it may reduce suicidality, though data are limited. Strategies to extend effects—multiple doses, maintenance, or additional medications—have shown mixed results. Alternative routes (intramuscular, intranasal, oral) show promise but lack sufficient data. Adverse effects are mainly mild, transient dissociative and sympathomimetic symptoms, indicating good tolerability. Ketamine's unique properties could shift depression treatment paradigms.
bioRxiv Preprint Server
January 6, 2023
Adelaida Castillo, Julien Dubois, Ryan M. Field et al.
3 citations
preprint
Ketamine reduced brain-wide low-frequency fluctuations and decreased prefrontal global brain connectivity in healthy adults, while also increasing pulse rate and electrodermal activity. A combination of neural and physiological metrics may predict subjective mystical experiences and reductions in depressive symptoms. The study used time-domain functional near-infrared spectroscopy to measure acute brain dynamics after intramuscular ketamine (0.75 mg/kg) or placebo in 15 participants within a clinical setting, demonstrating the feasibility of this neuroimaging method for larger clinical studies on psychedelics.
Journal of Psychoactive Drugs
November 22, 2024
Wesley C Ryan, Boris D. Heifets
2 citations
In an addiction psychiatry practice offering intramuscular ketamine with psychotherapy for depression, 70 patients received 1,114 sessions over nearly seven years. Induction produced an 82% response, and improvement remained above 80% after six months of maintenance sessions given every 21 days at a mean dose of 1.13 mg/kg. Many patients (38%) stayed in treatment for at least a year. Dropouts were mostly due to logistical reasons (50%); side effects accounted for only 9.7%. One case of ketamine use disorder required residential treatment. Nausea was the main side effect managed with medication. Maintenance ketamine-assisted psychotherapy extended benefits for mood, anxiety, and substance use and was generally well tolerated.