Why do people use drugs? The short answer is because they hope for some sort of beneficial effect. The long answer might depend on whether you are experimenting, whether you use regularly, or whether you're addicted.

The term addiction is not typically used when making a formal diagnosis. The terms Substance Dependence or Substance Use Disorder are usually used instead and there are a number of signs or symptoms used to make these diagnoses.

All drugs of addiction affect chemicals in the brain involved in reward, motivation and self-control. Repeated, frequent drug use can lead to changes in the brain that disrupt our priorities and influence our behaviour.