Results of a neuropsychological battery indicated statistically significant improvements in processing speed and executive functioning (including inhibition, cognitive flexibility, problem-solving, phonemic fluency, and working memory), both immediately after treatment and at 1 month. No declines were noted across any performance domain.
Interestingly, mean performances on these tests moved from the average to the high average score range relative to same-age peers and, in all but one instance, phonemic fluency was high average at baseline and improved to the superior range relative to same-age peers at the 1-month follow-up. Learning and memory tests showed a significant improvement in visual memory and verbal memory. Sustained attention showed a significant improvement in accuracy (detection) and a weak but significant slowing of reaction time, consistent with a prioritization of accuracy over speed and reduced impulsivity.
In a Scientific American article, lead researcher Nolan Williams said he suspects the powerful effects of psychedelics have to do with their “profound ability to increase plasticity in the brain” by “bringing it back to a more juvenile state where reorganization can occur.” People often experience a life review that appears in their minds almost like a slideshow. “It somehow drives a particular sort of psychological phenomenon that you don’t achieve through guidance,” Williams said.
The data from the MISTIC trial in Mexico may spur more research in the US. The National Defense Authorization Act, signed by President Joe Biden last December, authorizes service members diagnosed with PTSD or TBI to take part in clinical studies of any “qualified plant-based alternative therapies.”
“It’s all really timely,” Williams said. “From my perspective, we should have some traction to make a strong argument that the risk-benefit is right.”