MARION — The biggest revolution there is in psychiatry is that psychedelic medications can be carefully and cautiously administered under the right circumstances to certain patients suffering trauma, a renowned researcher and author told an audience of more than 500.

Dr. Bessel van der Kolk, a leading researcher into post-traumatic stress and author of New York Times best-seller “The Body Keeps the Score,” spoke about how the body experiences trauma during a Thursday, June 27 talk presented by the Marion Institute at Tabor Academy. 

Drugs like MDMA or ayahuasca are effective because they “open up a critical window of development,” van der Kolk said.

“It turns out that — all psychedelic agents — your mind becomes wide open to rearrange itself,” he said. “At that point, what comes into your mind, into your brain is the critical issue.”

More than 550 tickets had been sold for the event by Wednesday, according to the Marion Institute.

Among several other illuminations presented by van der Kolk, he shared how the brain and its organization is affected by traumatic experiences.

“Trauma sits in a more primitive part of your brain where you perceive danger and safety and the experiences of your body,” he said.

Van der Kolk showed imaging from extremely traumatized individuals that demonstrated activity in the right side of the brain — the emotional and spatial part. The right side of the brain “has no sense of time” and cannot distinguish between past and present, so terror is relived over and over again, he said.

Meanwhile, the left side of the brain — the “rational” part — shuts down as a result of trauma, according to van der Kolk. 

The speech center in particular is the area on the left side that shuts down; that’s why people who experience trauma cannot speak about it, van der Kolk said.