Dr. Casey Halpern — Chief of stereotactic and functional neurosurgery at the University of Pennsylvania School of Medicine. His lab develops engineered brain-stimulation devices to treat binge eating, bulimia, OCD, and other compulsive disorders.
The gist
Andrew Huberman talks with neurosurgeon Dr. Casey Halpern about using deep brain stimulation, ablation, and non-invasive methods to treat compulsive eating, OCD, addiction, and movement disorders. Halpern explains how his lab targets the nucleus accumbens to detect 'craving cells' and deliver brief, episodic stimulation that interrupts the urge-to-binge cycle. They discuss the 'two-hit' origin of eating disorders, why continuous stimulation loses effect over time, and the parallels between obesity, anorexia, and OCD as 'loss of control' disorders. The conversation also covers non-invasive tools like TMS and focused ultrasound, the power of self-awareness as a therapy, and Halpern's personal reflections on neurosurgical training, calm, and exercise.
Big reveals
- Halpern's lab published a Nature Medicine pilot study using responsive nucleus accumbens deep brain stimulation for loss-of-control eating.
- In mice, just two weeks of high-fat (60% fat) food can hijack and dysregulate normal nucleus accumbens function.
- Continuous stimulation loses effect via tolerance; intermittent, craving-triggered stimulation (published in PNAS) is the most robust and durable.
- Halpern calls cocaine addiction 'untreatable at the moment,' framing compulsion as 'urge despite the risk' common to OCD, addiction, and eating disorders.
- Contends that obese patients with food compulsion are 'more similar to anorexics than they are different' — both are compulsions despite risk.
- His team provokes binges in a lab 'food monitoring unit' with eye trackers and one-way mirrors; severe patients still binge despite full awareness.
- Cites a Stanford colleague's claim that ~75% of the world's antidepressant and anti-anxiety medication is consumed in the United States.
- Personal admission: gained significant weight as a junior resident, drinking sugary coffee late at night, then lost ~20 pounds via morning gym workouts.
Things worth remembering
- Halpern's daily work is deep brain stimulation plus transcranial focused ultrasound, but these are a tiny minority of overall neurosurgery.
- Some level of OCD can be an asset — famous CEOs, surgeons, and scientists may have controllable obsessive traits.
- Binge eating disorder is the most common eating disorder, affecting roughly 3-5% of the population.
- The nucleus accumbens is almost a centimeter in size — large relative to the 3-4mm targets neurosurgeons usually aim for.
- Severe binge eating patients typically binge only about once a day because the stomach limits intake; 'loss of control' can happen 20-30 times a week.
- Anorexia has the highest mortality of any psychiatric condition — patients die from both suicide and metabolic complications of being underweight.
- Essential tremor is about 10 times more common than Parkinson's and is the most common neurologic condition in people over 70.
- Surgeons can destroy 3-4mm of brain tissue (capsulotomy) or traverse parts of the brain with no detectable adverse effects on function.
- Only about 200,000 deep brain stimulation surgeries have ever been done, versus ~50 million Americans affected by these conditions.
- MRI-guided focused ultrasound is FDA-approved to ablate brain tissue for tremor non-invasively, with no incision.