two paths in a wood

I often think about the maxim that the most interesting findings occur at the intersections of fields. I recently discovered a book that lands at the intersection of literature, psychiatry, and neuroscience. It was a fabulous read.

I discovered this book in a tiny, one-paragraph blurb in the New Yorker; the book wasn’t even featured in an article. But it sounded interesting, so I bought it. I was not disappointed.

Projections, by Karl Deisseroth, is divided into chapters that each focus on a different psychiatric disorder. Each chapter, remarkably, examines its disorder from three perspectives: the patient (literature), the doctor (psychiatry), and research science, including the evolution of the brain and modern optogenetic research (neuroscience). Deisseroth is a wonderful storyteller, and his book is unique in examining problems from so many different angles.

Major Depression

I’d like to share part of the chapter on major depression. A patient presents in the emergency room with depression as a result of trauma. He has been in a tragic car accident and lost his wife. Inexplicably, he is unable to cry.

Deisseroth, the emergency psychiatrist on duty, talks to the patient and tries to determine what is going on and how to help. The chapter is a brilliant mosaic of the patient’s story, the doctor’s emotions, a discussion of major depression and its evolutionary role, and a discussion of optogenetic research into where tears are produced in the brain and why that part of the brain might malfunction.

Here, for example, is Deisseroth’s explanation of the role of bad feelings, including the bad feelings that occur during major depression, and why they probably arose evolutionarily:

“Life requires making choices between utterly distinct categories that cannot be compared directly. Subjectivity—feeling good or bad, for example—may be a sort of universal monetary instrument for the inner economy of the brain, allowing positivity or negativity from diverse pursuits, from food to sleep to sex to life itself, to be converted into a single common currency. This arrangement would allow difficult category-crossing decisions to be made and actions chosen—quickly and in a way best suited to the survival needs of the particular animal and its species.

This makes me feel somehow better about bad feelings. They actually have a purpose. They are a form of measurement for the brain. If one action feels better and one action feels worse, the animal goes for the better-feeling one.

Not that such simple calculations always work in the modern world. But actually, . . . the calculations of the brain can be amazingly complex. This is an interesting scientific explanation for the commonsense dictates to “follow your gut” and “listen to your conscience.” Your body is already working to compare and evaluate different choices; your job is simply to listen to whether it’s saying “good” or “bad.”

So perhaps persistent bad feelings are merely a sign that a change is needed?

But also—we can’t forget that the brain can sometimes get out of sync with reality and send out false signals.

There’s much to chew on here.

What’s making you feel good or bad today?