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

by Alex Korb

The important thing to understand about a pattern in the dorsal striatum is that once it’s there, it’s pretty much there for good. That’s why you never forget how to ride a bike. This is one of the reasons that bad habits are so hard to change. You don’t actually eliminate old habits—they just get weaker as you create newer, stronger ones. Furthermore, once habits are in the dorsal striatum, they no longer care about pleasure. Sure, they usually first get in there because your nucleus accumbens is motivating you to do something, but once a habit is really engrained, it no longer requires the nucleus accumbens to motivate it. That’s also how addictions work. Addictions start out as pleasurable impulses in the nucleus accumbens. But over time, the nucleus accumbens stops responding, and the addictions no longer feel pleasurable. But because they are engrained in the dorsal striatum, you feel compelled to have another drink or another cigarette anyway. Because of these changes in dopamine, addictions increase your risk of developing depression, and depression increases your risk of developing an addiction. Another downward spiral.