What is addiction?

A person is addicted when they are obsessed with something or someone, and their life centres on the object of their addiction.
Substance addiction is a condition of absolute dependence for the addict, whose actions are governed by their intense need for the substance. A person is physically dependent on a substance when their body adapts to the substance and produces withdrawal symptoms when the substance is not present.
A user is psychological dependent on a substance when they need it to feel good, to soothe stress or pressure, or simply to feel normal and able to respond to the demands of everyday life. Psychological dependence is more significant than physical addiction, and requires a lot more time to treat. Not all substances give rise to both forms of dependence.