The Upward Spiral: Using Neuroscience to Reverse the Course of Depression, One Small Change at a Time

by Alex Korb

Medical residents have to deal with long hours, late nights, difficult patients, and the fear that they’ll make a mistake and accidentally kill someone. In short, they’re stressed. On top of that, in order to become full-fledged doctors, they have to spend months studying intensely to pass their board-certifying exam. In short, they’re extra-stressed. To study the effects of chronic stress, researchers in Portugal performed fMRI scans on a stressed group of residents who had just spent three months studying for their board exam and compared them to a control group of residents who had no exam.5 The study found that stressed subjects acted more out of habit than intention. They kept making the same choices, even when those choices were rewarded less and less. Not surprisingly, the increased habitual behavior was caused by changes in processing within the habitual dorsal striatum. In addition, the stress caused the decision-making orbitofrontal cortex to actually shrink. The subjects were studied again six weeks later, after they’d gotten a chance to relax—and indeed, their dorsal striatum activity had returned to normal, as had the size of their orbitofrontal cortices. Stress biases the brain toward old habits over intentional actions, which is one of the reasons it is so hard to change coping habits—the things we do to deal with stress. One of the problems with coping habits is that if you don’t do them, you stay stressed. And if you try to suppress a coping habit, you’re ...