Addiction is now understood to be a brain disease. Whether it’s alcohol, prescription pain pills, nicotine, gambling, or something else, overcoming an addiction isn’t as simple as just stopping or exercising greater control over impulses.

That’s because addiction develops when the pleasure circuits in the brain get overwhelmed, in a way that can become chronic and sometimes even permanent. This is what’s at play when you hear about reward “systems” or “pathways” and the role of dopamine when it comes to addiction.

But what does any of that really mean?

This video explainer from Yale Medicine shows how addiction takes hold of the brain.