Essentials: Understanding & Healing the Mind | Dr. Karl Deisseroth

Andrew Huberman opens by asking Karl Deisseroth how neurology and psychiatry differ. Deisseroth puts the line at measurability. Psychiatry deals with disorders "where we can't see something that's physically wrong." For an individual patient, no blood test makes the diagnosis, and no brain scan identifies schizophrenia or depression. Neurologists, he says, can see a stroke on a brain scan or record seizure and pre-seizure activity with an EEG, then treat based on those measurements.

And so psychiatry is much more mysterious, and the only tools we have are words.

Rating scales for depression and autism give some structure, but Deisseroth points out that they are "still" words. He sees a paradox here: psychiatry is dealing with "the most complex, beautiful, mysterious, incredibly engineered object in the universe," and yet words are its only way in.

Huberman asks whether very talkative patients are easier to diagnose. Deisseroth agrees that, in principle, less speech makes diagnosis harder. Reduced speech can also be a symptom in its own right, as in depression, the negative symptoms of schizophrenia, and sometimes autism. Some patients are so depressed they cannot speak, and that makes it hard to tell depression apart from other reasons someone might be silent. He calls working through this "the art and the science of psychiatry."

Asked whether there will ever be a blood test for depression, schizophrenia, or autism, Deisseroth expects quantitative tests to arrive eventually. He notes that work is already underway to study brain rhythms with external EEGs. His reasoning is that psychiatric disease is physical: it comes from circuits, connections, and projections that are not working as they would in a typical situation. He grants that such tests could be abused or misused, but says that is true of all of medicine.

For the biggest challenge facing psychiatry today, Deisseroth names stigma rather than a technical gap, while noting that progress is being made. Patients often believe they should handle their problems alone, which can delay treatment and let symptoms worsen. His example: going a year or more with a serious, untreated anxiety issue can convert to depression, adding a second problem on top of the first. He accepts that people can sometimes master these problems on their own, but says "usually, some help is a good thing."

Huberman recalls an earlier lecture in which Deisseroth said we don't know how other people feel, and often don't even know how we feel ourselves. He notes that many words describe sadness, yet there is no objective way to compare them. Deisseroth sees a tension between clinical terms that mean something specific to physicians and the everyday use of the same words. When someone says "I'm depressed," that may not match what a clinician means by depression.