The psychedelic substance ibogaine has been shown to slow brain wave activity in individuals with traumatic brain injuries, potentially accounting for its effectiveness in treating symptoms of post-traumatic stress disorder (PTSD).

A study conducted last year revealed that ibogaine, sourced from the African Iboga plant, significantly enhanced the overall mental and physical well-being of military veterans suffering from traumatic brain injuries. Yet, the precise mechanisms behind these effects were previously unknown.

To investigate further, Jennifer Lismore from Stanford University and her team examined brain imaging of 30 individuals involved in the initial study. During a 5-day treatment session at a facility in Mexico, participants received a dosage of 12 milligrams of ibogaine per kilogram of body weight and participated in supportive activities like yoga, meditation, and therapy.

As part of the study, the researchers collected EEG data that recorded participants’ brain electrical activity. These scans were taken 2-3 days prior to and 3.5 days following the ibogaine treatment.

By comparing the EEG findings, Lismore and her team observed an overall deceleration in brain wave activity post-treatment, particularly in the gamma waves—the fastest brain waves—which exhibited nearly a 16% reduction in strength in the occipital region after ibogaine therapy. While gamma wave intensity saw a slight rebound after one month, levels remained significantly below those recorded prior to treatment.

Additionally, the intensity of slow theta waves rose by approximately 17% in the back of the brain and 13% at the front 3.5 days post-treatment. However, this increase lost its significance after one month.

Lismore suggests that the observed reduction in brain wave activity may clarify why ibogaine is effective for alleviating PTSD symptoms in many patients. “The deceleration of brain function has allowed patients, particularly those experiencing hyperawareness and sensitivity associated with PTSD, to find relief,” she noted. “One way to understand this slowing process is as a mitigation of the heightened distress often seen in PTSD cases.”

The temporary spike in slow theta waves could also indicate that ibogaine promotes neuroplasticity—the brain’s ability to adapt and rewire itself. Previous studies in animals have associated theta wave activity with brain adaptability, Lismore explains. By inducing a short-term increase in theta wave presence, ibogaine may create conditions conducive to improving mental health.

“Ibogaine essentially addresses the chaotic, restless nature of the brain, facilitating a sort of normalization,” remarked Conor Murray from the University of California, Los Angeles. “Ultimately, it instills a sense of security for participants, reassuring the brain.”

However, he cautions that these findings don’t fully reveal the mechanisms through which ibogaine effects these brain changes.

Another challenge is the absence of control measures, complicating the assessment of the influence from other treatment components, points out Lismore. Nonetheless, she asserts that these insights represent “a significant first step toward understanding why this treatment is so impactful.”