A Lesser-Known Psychedelic Drug Shows Promise for PTSD Treatment

Ibogaine, derived from a central African shrub, has been used in rituals for two millennia. But in a small study, it appeared to reduce symptoms of PTSD among veterans

pressed leaves in a museum collection with notes
Leaves from the iboga plant, collected in 1933 from Angola. The psychedelic drug ibogaine can be derived from the plant's root bark. Smithsonian Institution under CC0 1.0 DEED

From MDMA to the hallucinogenic psilocybin in magic mushrooms, psychedelic drugs have been gradually gaining interest as treatments for mental health conditions in recent years. Following a new study, researchers now suggest another, little-known psychedelic could be added to that list: a plant-based drug named ibogaine.

In the small study, published in Nature Medicine last week, 30 male combat veterans with traumatic brain injury and a history of exposure to repeated blasts seemed to experience reduced psychiatric symptoms after treatment with ibogaine.

One month after a single treatment with the drug, participants reported an average reduction of 88 percent in PTSD symptoms, 87 percent in depression symptoms and 81 percent in anxiety symptoms, reports Nature News’ Max Kozlov. Cognitive function also appeared to improve after treatment, and the only reported side effects were headaches and nausea.

“Before the treatment, I was living life in a blizzard with zero visibility and a cold, hopeless, listless feeling,” Sean, a study participant, says in a statement. The 51-year-old veteran has been deployed on six combat tours and credits ibogaine with saving his life. “After ibogaine, the storm lifted.”

Ibogaine is a naturally occurring compound in the roots of iboga shrubs, which are native to central Africa. In Gabon, an estimated 115,000 citizens practice Bwiti, a spiritual discipline that utilizes iboga roots in an initiation ceremony, reports Rachel Nuwer of National Geographic. The first legally exported iboga from Gabon left for Canada in March 2023, where it was distilled for Ambio Life Sciences, the clinic used by the study researchers.

The United States has classified ibogaine as a Schedule I drug since 1970, meaning that it has no accepted medical use. This has made most studies of the substance impossible, per National Geographic. But for the recent research, the scientists and study participants traveled to a clinic in Mexico, where ibogaine is currently unregulated.

“There were a handful of veterans who had gone to this clinic in Mexico and were reporting anecdotally that they had great improvements in all kinds of areas of their lives after taking ibogaine,” study co-author Nolan Williams, a psychiatrist and behavioral scientist at Stanford University, says in the statement. “Our goal was to characterize those improvements with structured clinical and neurobiological assessments.”

The study participants had independently received grants from Veterans Exploring Treatment Solutions, a non-profit that assisted them in scheduling ibogaine appointments and flying to the clinic in suburban Tijuana. Ibogaine has been associated with heart problems, so the doses were paired with intravenous magnesium to minimize the risk. Medical staff, not the researchers, administered the doses. The clinic was “a fundamentally grassroots thing,” and the scientists relied on observations and reported effects from veterans, Williams tells USA Today’s Eduardo Cuevas.

Traumatic brain injuries, or TBIs, are some of the leading causes of PTSD. Hundreds of thousands of troops who served in Afghanistan and Iraq have reportedly suffered TBIs over the last two decades, according to the U.S. Department of Veterans Affairs. TBIs are associated with several conditions beyond PTSD, including the major depressive disorder and suicidal ideation reported by some study participants. Wired’s Emily Mullin writes that while commonly prescribed antidepressants and anti-anxiety medications may treat PTSD symptoms, the underlying brain injury remains unaddressed with these methods.

Experimental treatments with psychedelics, however, are thought to facilitate new connections between cells in the brain, though scientists don’t know for sure how they work, per Wired. Ibogaine, in particular, might affect the same serotonin transporter that selective serotonin reuptake inhibitors (SSRIs) target to treat depression.

“No other drug has ever been able to alleviate the functional and neuropsychiatric symptoms of traumatic brain injury,” Williams says in the statement. “The results are dramatic, and we intend to study this compound further.”

Researchers have previously studied ibogaine as a potential treatment for opioid or cocaine dependence. While the recent study is one of the earliest to investigate ibogaine in relation to PTSD, the psychedelic compounds MDMA and psilocybin are in late-stage trials for PTSD treatment.

Alan Davis, a clinical researcher at Ohio State University who is unaffiliated with the study, tells Nature News that he agrees the data support launching trials to further test ibogaine. However, he says that MDMA and psilocybin may currently be better candidates for veterans’ PTSD treatment. He is not the only researcher looking at the study’s results with caution.

“Although the results have large effect sizes, most psychological studies will show improvement with any intervention,” says Amy Badura Brack, a psychologist at Creighton University who was not involved with the study, to Wired.

Though its results appear promising, the study did have some drawbacks. It was limited to a small sample size, lacking both participant diversity and a placebo arm. Researchers plan to continue monitoring study participants, publish the results and launch future research to better understand ibogaine and TBI treatment.

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