Why is drug addiction labeled a disease?

Impairment: Drug addiction or any other addiction becomes labeled as a disease when it causes impairment in function, for example not being able to take care of oneself or basic functions. For example, when one uses alcohol to the degree that one stops eating a balanced diet or obtaining basic medical or dental care and puts oneself or others at risk.

Psychiatric disease: 1. It's a psychiatric disorder, and those are diseases by definition. 2. There are changes in the brain (and perhaps body) from chronic drug abuse. 3. There are some data suggesting a genetic predisposition to addiction.

See below: People who are addicted didn't choose to be addicted. More evidence that there is a strong genetic component, that an addicts brain is different even before they ever ingest an addictive drug. Their brain responds different to rewards. And once in place the chemistry and nerve changes make it difficult to arrest. But like other chronic diseases, it does respond to treatment, not unlike diabetes.