How Would You Define “Addiction”?

Question by mandybethg: How would you define “Addiction”?
I don’t mean a dictionary definition. But at what point would you say someone is addicted to something? Drugs, alcohol, food, etc.

Best answer:

Answer by peanut
When they become powerless to control their usage and their life has become unmanageable.

Know better? Leave your own answer in the comments!