With the claustrum turned down, Barrett said, his team has also noticed that a network of regions called the default mode network can go quiet as well. This network is active when we think about ourselves, so its dawdling may contribute to the feeling of egolessness that so many psychedelics users report. Research has shown that people who struggle with depression, anxiety, or other mental health conditions have difficulty recovering in part because their default mode networks are stuck in a rut—that “default” setting—which can include a powerful cycle of repetitive, negative thoughts and behaviors that only get stronger as they replay. 

But the sudden upheaval wrought by the claustrum’s mushroom-induced coffee break seems to have the potential to jolt the brain out of this cycle. “It may be that in this state, the normal repetitive thoughts that are baked into some neural circuits after years and years of use become less strong,” Barrett said. That may leave room for other, usually quieter circuits to have a say.

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He compares the situation to a theater production in which the director suddenly leaves. The actors don’t know what to do, so they just keep saying their lines, sometimes all at once or out of order. “You may come out with a performance that is just completely disorganized,” he said. “Or you may come out with a performance that’s rearranged in a very interesting way that nobody had thought of before.” Barrett points to this dynamic as one reason psychedelic therapy may have so much potential to treat mental health conditions. In normal talk therapy, “you’re battling the circuitry that you’ve built up over a long period of time,” he says—instead of radically reorganizing it.

The profound transformations some study participants have experienced through psychedelic-assisted therapy may be possible because when the claustrum’s control is disrupted, the brain becomes more “plastic,” or flexible and open to change, Barrett said. Plasticity may be key to at least allowing that growth to happen, but it’s only the first step. 

“Simply making the brain more plastic itself doesn’t necessarily always lead to a positive outcome,” he added. A controlled environment with trained therapists to guide and support the person during and after the experience is crucial to promoting that plasticity, “which can lead to learning, which can lead to healing and growth.” 

Watch: Can Psychedelics Cure?

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