(p. C4) New studies suggest that psychedelics, carefully administered in controlled settings with trained therapists, can help treat mental illnesses like depression, addiction and PTSD. But just how do psychedelics achieve these therapeutic effects?
A new study in the journal Nature by the neuroscientist Gul Dolen at Johns Hopkins and colleagues tackles this question.
. . .
. . ., Dolen’s team gave mice a variety of psychedelics and observed their effects. Mice, like people, have what are called “critical periods” for various kinds of development—times when the brain is especially open to new experiences and especially likely to learn and change. After a critical period closes, that type of learning is much harder. These specific critical periods reflect a more general phenomenon: Brains start out more “plastic,” easier to change and more sensitive to experience, and get more efficient but more rigid as people—or mice—grow older.
. . .
As expected, the different drugs acted through different chemical mechanisms. But all of them ultimately activated genes that made the brain more “plastic,” more easily changed.
Other research shows that psychedelics may reopen other kinds of critical periods. For example, amblyopia, or “lazy eye,” must be treated early for the visual cortex to rewire properly. But a 2020 study published in Current Biology found that ketamine reopened the visual critical period in mice, allowing older animals to recover from amblyopia.
These results have important implications for psychedelic therapy. We know that the effects of psychedelics depend on “set and setting”—the context and the attitude of the person who takes them—and that psychedelic experiences can feel wonderful or terrible to the user. The new research suggests that psychedelics work by opening up the brain to new possibilities, allowing it to escape from old ruts, change and learn. That might give humans a chance to change addictive habits or destructive thought patterns.
For the full commentary, see:
(Note: ellipses added.)
(Note: the online version of the commentary has the date July 20, 2023, and has the same title as the print version.)
The academic article discussed in the passages above is:
Nardou, Romain, Edward Sawyer, Young Jun Song, Makenzie Wilkinson, Yasmin Padovan-Hernandez, Júnia Lara de Deus, Noelle Wright, Carine Lama, Sehr Faltin, Loyal A. Goff, Genevieve L. Stein-O’Brien, and Gül Dölen. “Psychedelics Reopen the Social Reward Learning Critical Period.” Nature 618, no. 7966 (June 14, 2023): 790-98.