Dr Nolan Williams Psychedelics Neurostimulation For Brain Rewiring

High-Level Overview

Andrew Huberman talks with Dr. Nolan Williams, a Stanford psychiatrist and neurologist (the episode is released in his memory) whose Brain Stimulation Lab develops new treatments for severe depression and trauma. They cover why depression is so disabling, how transcranial magnetic stimulation (TMS) reveals a direct link between a mood-regulating brain region and the heart, and why depression may be better understood as a circuit problem that can be recalibrated than as a "chemical imbalance." From there they tour psychedelic medicine: ketamine, psilocybin, MDMA, ibogaine, 5-MeO-DMT and ayahuasca, along with cannabis, alcohol, sleep-deprivation therapy, and Dr. Williams's rapid TMS protocol, known as SAINT or SNT.

The tone is curious, rigorous and hopeful. Dr. Williams describes himself as agnostic about which tool works, focused only on helping patients, and he repeatedly stresses medical supervision and well-designed trials, insisting that psychedelics should never be recreational. Huberman brings his neuroscience questions and some personal candor, including a lifelong "knock on wood" compulsion. The conversation moves from brain circuitry to the history and evidence for each treatment, ending with a treatment that can lift severe depression within days.

The Discussion Explores:

• Depression's burden: why it is the most disabling condition worldwide and a risk factor for heart disease.
• The brain-heart circuit: how stimulating the left dorsolateral prefrontal cortex slows the heart, and left-right balancing of mood.
• Prefrontal "governance": how the prefrontal cortex normally leads the cingulate, and how depression flips that timing.
• Ketamine and the opioid system: a study showing its antidepressant effect depends on opioid receptors, not the "trip."
• SSRIs and "psychiatry 3.0": moving from chemical imbalance to fixable circuits.
• Psychedelics: evidence for MDMA in PTSD and psilocybin in depression, the role of "letting go," ibogaine, 5-MeO-DMT and ayahuasca.
• Cannabis, alcohol and sleep: THC versus CBD, relative drug harms, and triple chronotherapy.
• SAINT/SNT: an accelerated, individually targeted TMS protocol that can bring remission in days.

Deep Dive into Main Ideas

Why Depression Is So Disabling

Dr. Williams explains that depression covers a wide range of presentations, from loss of interest to anxious overactivity to low-motivation underactivity, and his lab works with Conor Liston at Cornell to identify brain-imaging "biotypes." He says "Depression is the most disabling condition worldwide." Moderate depression is about as disabling as an acute heart attack, and severe depression as disabling as untreated cancer. The American Heart Association recently added depression as the fourth major risk factor for coronary artery disease, alongside high blood pressure, high cholesterol and diabetes, and having a heart attack in turn raises the risk of depression.

His clinical focus is the most acute cases. In cardiology, the sicker you are, the more tests and treatments become available, from a doctor's office to the ER to the ICU. In psychiatry, he says, as a person moves from depressed to suicidal, the number of treatments on average actually goes down, and there are no tests. Trained as both a neurologist and psychiatrist, he wanted to bring neurology's acute, brain-based tools to psychiatry.

The Brain-Heart Circuit and Left-Right Mood Balance

TMS uses a magnetic pulse to induce electrical current in brain tissue, bypassing the skull. When Dr. Williams's group stimulates the left dorsolateral prefrontal cortex (DLPFC), which he calls a "governor" of the brain, the signal spreads through the anterior cingulate, insula and amygdala down to the vagus nerve and the heart. Each two-second train of stimulation drops heart rate by about 10 beats per minute, time-locked to the pulses, an effect not seen when stimulating visual or motor cortex and replicated four or five times, including by Martijn Arns's group in the Netherlands. The heart rate drop mainly signals that they're in the right network; it explains only a small part of the mood effect, and simply lowering heart rate, for example with beta blockers, is unlikely to treat depression. He notes lower heart rate variability is linked to moderate to severe depression in many studies.

Mood also seems balanced between hemispheres. Dr. Williams cites Mike Fox at Harvard, who mapped strokes onto a large human connectome database: strokes that cause depression are all connected to the left DLPFC, while those causing mania connect to the right. Exciting the left or inhibiting the right is antidepressant. Implanted vagus nerve stimulators can also relieve depression, and for mild depression, behavioral interventions like meditation and exercise work well. But he describes a "volitional threshold": as depression deepens, thoughts become semi-voluntary and harder to control, and at the extreme, in catatonia, people get stuck.

When the Players Coach the Coach

Different parts of the left DLPFC do different jobs. With David Spiegel, Dr. Williams found that inhibiting a cognitive-control area (the one involved in the Stroop task, where you name the ink color of a mismatched word) increased people's hypnotizability, while a different subregion, connected to the emotional subgenual anterior cingulate, is the target for depression. The cingulate acts as a conflict detector that is overactive in depression. In healthy people, the DLPFC activates just before the cingulate; in depressed patients, the cingulate leads. Effective SAINT treatment flips the timing back, and the more it does, the greater the antidepressant effect. Huberman likens it to a game where the players have started telling the coach what to do.

Dr. Williams describes TMS as "almost like exercise for the brain," and notes that therapy can restore this control in milder depression. Patients who had been told they weren't trying hard enough in therapy often report that, after rapid TMS, they could suddenly understand their therapy books. Several patients who reached remission early in the five-day protocol described sitting at the beach, fully present, in a way they'd only read about in mindfulness books.

Ketamine, Dissociation and the Opioid System

Ketamine's antidepressant effect correlates with how much dissociation people experience, which Dr. Williams calls "necessary but not sufficient." In his crossover study, the same patients received ketamine with either 50 milligrams of naltrexone, an opioid blocker, or a placebo. Naltrexone dramatically blocked ketamine's antidepressant effect, yet the dissociative experience was identical both times. This challenged the popular idea that the psychedelic "trip" alone is what heals, and suggested the opioid system plays a role in mood. A related TMS study found an opioid blocker also blocked TMS's pain relief, and patients with depression needed three times the opioid dose after knee replacement surgery. He notes opioids may be antidepressant short-term but, used chronically, strongly pro-depressant. Huberman adds that labs, including one at UC Davis, are engineering psychedelic-like compounds without hallucinogenic effects that still shift mood in animals, which Dr. Williams says remains to be shown in humans.

SSRIs and "Psychiatry 3.0"

Dr. Williams says SSRIs clearly work for a subpopulation of people with depression, OCD, generalized anxiety and panic, but because they take weeks to work, their benefit likely comes from plasticity (for example, increased BDNF) rather than simply more serotonin. He agrees the idea that people are born with a serotonin deficit, a "chemical imbalance," is wrong, which psychiatry has known for some time. He frames three eras: psychiatry 1.0 focused on family and childhood experiences, 2.0 on chemical imbalance, and 3.0 on circuits. TMS lifts depression with no serotonin involved, and imaging shows ketamine, psilocybin and SAINT all change the same connections, between the subgenual cingulate and the brain's default mode network.

The message this sends patients matters: their illness is a recalibratable circuit, not something permanently missing or an inescapable result of childhood. Some patients who relapse tell him, "I'll never think about killing myself again," because they know treatment can bring them back. Huberman compares this to a friend who regained weight but knew exactly how to lose it again.

MDMA, Psilocybin and the Power of "Letting Go"

Why would the brain hold on to unhelpful rules? Dr. Williams gives an evolutionary answer: stress eating once prepared us for famine, and a veteran diving behind a car at a loud noise in San Francisco would be adaptive on a battlefield. Psychedelics may open a highly plastic state in which memories can be recalled and reconsolidated differently. For MDMA, one to a few sessions in trials produced a clinically significant PTSD improvement in about two-thirds of people, with an effect size he compares to antacids for heartburn, and in earlier trials relief lasted years for some. For psilocybin in depression, open-label studies show about half to two-thirds improving and blinded trials about a third, from results released so far. Ketamine's effect, by contrast, lasts about a week and a half on average. He notes blinding is a major challenge, and that ketamine plus naltrexone might serve as a useful placebo.

On safety, Huberman recounts that a widely cited paper claiming MDMA kills serotonin neurons turned out to have used methamphetamine. Dr. Williams cites a study of members of the Latter-day Saints faith who used only MDMA, which found no cognitive differences from non-users, plus neuropsychological testing from early MDMA trials showing no harm, suggesting little risk at one to a few doses. On psilocybin, imaging by David Nutt and Robin Carhart-Harris found overall brain activity decreases while global connectivity increases. Huberman raises Matthew Johnson's observation that "letting go" matters during psilocybin sessions. Dr. Williams connects it to exposure and response prevention for OCD: he once left a patient's car lights on for an hour to show the battery would be fine, after which the fear vanished. Huberman shares his own compulsive knock-on-wood habit, and Dr. Williams reassures him that normal isn't zero on psychiatric scales; it becomes a disorder only when it seriously impairs functioning.

Ibogaine, 5-MeO-DMT and Ayahuasca

Ibogaine comes from the root bark of the iboga tree in Gabon, used as a sacrament by the Bwiti; Dr. Williams recommends Daniel Pinchbeck's book Breaking Open the Head for more. Unlike psilocybin or LSD, it produces no visual changes with eyes open. With eyes closed, people re-experience earlier life memories, like the movie Minority Report, with detached empathy for themselves and others. It lasts 24 to 36 hours, is described as "10 years of psychotherapy and a night," and is "in no way a recreational substance." It carries cardiac risk, which can be greatly reduced by screening with an electrocardiogram. With donor funding, his team conducted the first full neurobiological study of former Navy SEALs, Army Rangers and other special operators who had traveled to Mexico for ibogaine. Early reports are dramatic, with no cardiac issues, and many veterans describe finally forgiving themselves for moral injuries. They separated ibogaine from 5-MeO-DMT, from the Sonoran Desert toad, which was given in a separate session a month later.

Ayahuasca, used as a sacrament in South America, combines one plant containing DMT with another containing a reversible MAO inhibitor that keeps the DMT from being broken down in the gut. Dr. Williams marvels that someone found this combination among 10,000 to 20,000 Amazonian plant species, and notes that a standard psychiatric MAO inhibitor could instead cause serotonin syndrome. Studies suggest it is safe, including in children exposed to small sacramental doses. In a Brazilian study, prisoners given an ayahuasca session had significantly lower rates of returning to prison than controls, though he stresses this is not a recommendation to give psychedelics to prisoners. He is emphatic: "these drugs can't be recreational drugs." If an SSRI requires a prescription and close follow-up, psychedelics should be used only under strict medical supervision.

Cannabis, Alcohol and Relative Harms

Dr. Williams says cannabis effects depend largely on the ratio of THC to CBD. CBD is anti-epileptic and anti-psychotic, as seen in the THC-free strain Charlotte's Web and in trials for severe childhood seizure disorders, while THC is pro-psychotic and pro-epileptic; high-THC products have caused psychosis that resolves once THC clears. Humans have bred CBD out of many strains. He would not want a teenager using cannabis before the prefrontal cortex matures, around 25, though he sees occasional use by a healthy adult as relatively safe for most people. Huberman cites a Lancet Psychiatry report linking early use of potent cannabis to later psychosis.

He also cites a David Nutt analysis ranking drugs by combined personal and societal harm, which placed alcohol as the most harmful, ahead of heroin and cocaine, with psilocybin at the other end. Both marvel that alcohol is served at university and hospital events, and Dr. Williams predicts it will go the way of doctors smoking in the 1950s and 1960s.

Triple Chronotherapy and Sleep

A single night of sleep deprivation can lift depression, but the effect vanishes after the next sleep. Triple chronotherapy, developed with a Stanford colleague, combines sleep deprivation, a shift in the sleep phase and bright light to re-entrain the circadian rhythm, producing a durable antidepressant effect in trials. Dr. Williams warns it must be done under medical supervision, since sleep deprivation raises anxiety, and notes it is underused partly because there's no insurance billing code for it. For everyday mood, he emphasizes regular sleep, blocking blue light at night, and the CBT-I rule of using the bed only for sleep and intimacy.

SAINT: Accelerated, Targeted TMS

TMS for depression began with Dr. Williams's mentor, Mark George, who combined findings of an underactive prefrontal cortex in depression with evidence that TMS could excite motor cortex. The approach gained FDA clearance around 2008. Dr. Williams sees a TMS device as "like a pharmaceutical company for you": the device is just the delivery layer, and the treatment is the protocol. A 2005 study showed that theta burst stimulation mimicking hippocampal rhythms changed brain excitability for an hour after only minutes of stimulation. Drawing on spaced learning (like studying note cards once an hour rather than cramming one card), his team found that sessions spaced about an hour apart enlarge more dendritic spines, which ketamine also does.

SAINT, now called Stanford Neuromodulation Therapy (SNT), gives 10 sessions a day, hourly, for five days, totaling about 90 minutes of stimulation across 50 hours, five times the standard dose, or about seven and a half months' worth. Each person's specific DLPFC target is located with brain scans rather than skull measurements. Depending on the study, 60 to 90% of patients reach full remission within one to five days, without side effects like the numbness, GI issues or reduced sexual interest some people experience with SSRIs, though durability varies, from a year to four years for some. Former students at Magnus Medical have obtained FDA clearance, and about a thousand patients are being recruited for trials across the country at BSL.stanford.edu, with ways for those who first receive the sham version to eventually get the real treatment.

Conclusion

Dr. Nolan Williams offers a hopeful, circuit-based view of depression: not a lifelong chemical deficit, but a recalibratable imbalance in which emotional conflict signals overpower the prefrontal cortex. TMS, psychedelics like MDMA, psilocybin and ibogaine, ketamine and even sleep-based therapies appear to converge on restoring that balance, often far faster than traditional treatments, though each carries risks and belongs only under medical supervision and in rigorous trials. His SAINT/SNT protocol shows how spacing and precise targeting can bring remission in days. Thoughtful, candid and grounded in evidence, this conversation is a moving and valuable look at the future of psychiatry, and well worth hearing in full.

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