New Scientist
A Stanford study found that the psychedelic drug ibogaine eased PTSD symptoms in veterans with traumatic brain injury by slowing fast brainwaves and briefly boosting slower ones. Researchers say this shift in brain activity may reduce hyperarousal and support the brain’s ability to rewire itself.
How a psychedelic may treat PTSD
Author: Grace Wade
PEOPLE with traumatic brain injury often experience post-traumatic stress disorder (PTSD), and the psychedelic drug ibogaine seems to alleviate these symptoms – which it may do by slowing down brainwaves.
Last year, a study found that ibogaine – a psychedelic substance derived from the African iboga plant – significantly improved mental and physical health in military veterans with traumatic brain injury. But it wasn’t clear how the drug produced these effects.
So, Jennifer Lissemore at Stanford University in California and her colleagues analysed brain scans of the original study’s 30 participants, all of whom were men from the US with traumatic brain injury, and most of whom also had PTSD. The participants had received ibogaine at a dose of 12 milligrams per kilogram of body weight during a five-day stay at a treatment facility in Mexico. They also saw a therapist, and had access to activities like yoga.
Throughout the original study, researchers took electroencephalogram (EEG) recordings – which measure electrical activity in the brain – of the participants. These scans were collected two to three days before ibogaine therapy, 3.5 days after and again one month later.
Comparing those EEG results, Lissemore and her colleagues found that, on average, faster brainwaves decreased in strength after ibogaine therapy, while slower ones did the opposite. For instance, days after taking ibogaine, the strength of gamma waves – the fastest type of brainwave – fell nearly 16 per cent, on average, in brain regions at the back of the head. These waves increased slightly in intensity one month later, but were still significantly lower than before the therapy.
Meanwhile, the intensity of slower, theta waves increased almost 17 per cent in the back of the brain and 13 per cent in the front of the brain 3.5 days after taking ibogaine. However, this difference was not significant one month later (Nature Mental Health, doi.org/p2pn).
The slowing of brainwaves may explain why ibogaine reduced PTSD symptoms for most participants
Lissemore believes the slowing of brainwaves may explain why ibogaine reduced PTSD symptoms for the majority of participants. “The slowing of brain activity went hand in hand with patients who were struggling with hyperarousal, hypervigilance and PTSD symptoms,” she says. “Those symptoms were improved drastically, and so one way to think of this slowing of brain activity is [as] a decrease in that hyperarousal that is a problem in PTSD.”
The temporary increase in slower theta waves suggests ibogaine induces neuroplasticity, or the brain’s ability to rewire itself. Studies in rodents have linked theta waves to plasticity in the brain, says Lissemore. By inducing short-term increases in theta waves, ibogaine may allow the brain to remodel itself in a way that improves mental health, she says.
“Ibogaine is basically targeting this very messy, restless brain and allowing it to kind of normalise,” says Conor Murray at the University of California, Los Angeles. However, we still don’t know exactly how it induces these changes, he notes.
Credits: TCA, LLC.