Aaron Rodgers fumbles the science on psychedelics. Drugs like ayahuasca can alter the brain—but how?

Scientists believe psychedelic drugs can change your mind. How this process actually takes place is still a mystery

By Troy Farah

Science & Health Editor

Published September 29, 2022 5:45PM (EDT)

Aaron Rodgers #12 of the Green Bay Packers (Dylan Buell/Getty Images)
Aaron Rodgers #12 of the Green Bay Packers (Dylan Buell/Getty Images)

Green Bay Packers quarterback Aaron Rodgers has been vocal about the positive benefits he's experienced from using ayahuasca, a hallucinogenic brew from the Amazon which some research suggests has rapid antidepressant properties that quickly evaporate suicidal urges and can potentially treat addiction.

But Rodgers insists that ayahuasca isn't a drug.

"It has properties in it that have hallucinogenative [sic] abilities," Rodgers said during a recent appearance on "The Pat McAfee Show," describing the exact behavior of a drug. "But it's not a drug. We're talking about plants here."

It wouldn't be the first time that Rodgers fumbled the science on a health topic. While ayahuasca specifically refers to a drink mixture of at least two plants, other plant-based substances are often swirled in, many of which contain drugs such as DMT (N,N-Dimethyltryptamine) or harmine. Otherwise, no one would likely drink it. It's a little like saying decaf coffee would be a good backup player for espresso.

Psychedelics like ayahuasca are becoming increasingly popular — and not just among folks like Rodgers who can afford trips to Peru. In recent years, interest in LSD (sometimes called "acid") and psilocybin "magic" mushrooms has exploded. Author Michael Pollan has wrung a popular book and Netflix series out of the idea that these drugs can "change your mind," gripping Western audiences who are plagued by mental malaise.

Based on a huge volume of psychedelic research, that appears to be the case: These drugs can create long-lasting changes in the brain that seem to alleviate depression, anxiety and other mental health disorders. But how exactly is this accomplished? Putting aside semantic debates, what is it that makes psychedelics so life-altering?

A new paper in the journal Neuropsychopharmacology briefly summarizes what we know — and what we don't — about the impact psychedelics have on the brain. Peeking under the hood, two scientists from the University Center for Psychiatric Research at the University of Fribourg in Switzerland, reviewed the available evidence to pinpoint what doses are necessary, where in the brain these changes occur, how long they last and whether any of this actually has any real therapeutic value.

Scientists used to think the brain all but stopped developing after a certain age. We now know that isn't true.

Much of this psychedelic research hinges on a concept called neuroplasticity, or the brain's ability to "modify, change and adapt," as one article puts it. Scientists used to think the brain all but stopped developing after a certain age. We now know that isn't true — using drugs and other methods, we can induce changes in the brain no matter how old.

But experts still aren't entirely sure how this happens on a neurological level. Answering this question is crucial to understanding how the brain works, as well as developing tools (i.e. drugs) to keep it thriving and healthy.

A lot of psychedelic neuroplasticity research, however, is in animals — not humans. It's not easy to measure brain changes in a living person, but feeding rats or mice psychedelics and measuring the size of neurons before and after a dose can teach us a lot about what may or may not be happening.

One of the most important aspects of psychedelics is the shape of the molecules. If you look at the chemical structure of drugs like LSD, psilocybin, DMT and 5-MeO-DMT (also known as "toad venom"), they all appear very similar to serotonin, a chemical that is widely used in the body for many biological processes — especially for keeping the brain online. Consequently, serotonin has been associated with numerous psychiatric and neurological conditions, such as schizophrenia and autism.

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Psychedelics are like keys that have almost — but not exactly — the same shape as serotonin. It's a close enough fit that these drugs can slip into the "locks," or receptors, in cells, creating downstream effects on the genes responsible for growing new brain cells and strengthening the connections between existing neurons.

Most brain changes appear related to brain-derived neurotrophic factor (BDNF), a protein our bodies naturally creates to regulate the nervous system. It not only plays a critical role in memory but also appears to encourage the biological processes associated with neuron growth. Psychedelics seem to boost levels of BDNF. In fact, after introducing psilocybin to a mouse brain, you can watch this growth in almost real-time.

Our brains are filled with billions of neurons, each of which have long, dangly threads called dendrites. BDNF is like fertilizer for neurons, coaxing them to grow big bushy dendrites, creating more connections in the brain. A forest of healthy neurons is associated with positive mental health, whereas conditions like PTSD and depression are associated with low levels of BDNF.

Some evidence suggests that psychedelics can create a feedback loop between different receptors, producing large quantities of BDNF. This effect can last for several days, or what the Swiss researchers call the "window of plasticity," and it can help humans become more responsive to therapy or recover from injuries like strokes. What's more, the effects seem to be long-lasting, persisting for as long as a month in some individuals.

However, "prolonged experiences of anxiety and distress during a state of heightened plasticity have the potential to be damaging," the authors warn. If someone under the influence of psychedelics has a traumatic experience, it could rewire the brain in a way that is unpleasant. One example is hallucinogen persisting perceptual disorder (HPPD), a condition in which some of the effects of psychedelics, such as hallucinations and psychological distress, persist long after the drug has worn off.

"Neuroplasticity may not only play a role in positive long-term effects of psychedelics, but also undesirable ones," the authors caution. Thankfully, these side effects are relatively rare and can be managed by taking the drugs in safe settings or with a therapist or guide.

There's a lot about the brain we still don't know, let alone when a powerful psychedelic drug is added to the mix.

While these are some of the dominant theories on how psychedelics change the brain, they're still theoretical. There's a lot about the brain we still don't know, let alone when a powerful psychedelic drug is added to the mix. For example, DMT (the main ingredient in ayahuasca) may involve receptors other than serotonin like the sigma-1 receptor.

To be certain, we need stronger evidence — including using human test subjects. The more we investigate the effects of drugs on the brain, the more we learn about how this magnificent metabolic machine works on its own.

We shouldn't expect a football player such as Rodgers to score a touchdown on a subject as complex as neuroscience. Even experts are still unraveling this interesting phenomenon. The proof is in the pudding, and Rodgers' experiences on drugs are valid. Only he can say if his ayahuasca trips are positive or life-affirming, but we can insist on correct terminology. "Drug" isn't a dirty word: Psychedelics are drugs, and these substances have a lot to teach us about ourselves.

By Troy Farah

Troy Farah is a science and public health journalist whose reporting has appeared in Scientific American, STAT News, Undark, VICE, and others. He co-hosts the drug policy and science podcast Narcotica. His website is and can be found on Twitter at @filth_filler

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Aaron Rodgers Analysis Dmt Drugs Lsd Neuroscience Psilocybin Psychedelics