Why it's hard to give up

Saying "No" to drugs, to unhealthy foods. But it doesn't always work, because people sometimes say yes. But a group of scientists are looking at the amount of dopamine in a person in your brain. People get a higher amount of dopamine in the brain when drug addicts see drugs. People lose the dopamine receptors when they do drugs. It is very hard to stop, if not impossible if you lose a lot of your dopamine receptors.