Individuals who are addicted to heroin will endure many of the withdrawal symptoms to reduce their tolerance for the drug, only so they can once again experience the rush.
Physical dependence to amphetamine occurs when the body has adapted to the presence of these drugs, and withdrawal symptoms occur if its use is stopped abruptly.
Prescription drug abuse means that an individual is taking a prescription medication that is not prescribed for them to get high, or taking it for reasons or in dosages other than as prescribed.
Individuals who have taken an antidepressant drug for longer than 6 weeks are particularly at risk of withdrawal if they abruptly stop taking the drug.