Types of Abuse   Psychological Dependence A person has become psychologically dependent on a drug when he or she feels a strong craving for the harmful substance because it produces pleasurable feelings or relieves stress or anxiety.   Physical Dependence A person has become physically dependent on a drug when he or she needs larger and larger doses to achieve the same desired effect. The person usually needs to take more and more of the drug since the body has built up tolerance to the effects of the drug. Sometimes, a person takes so much of a drug that it causes intoxication or an overdose.   Substance Dependence The person becomes intoxicated or high on a regular basis, whether it be everyday, every weekend, or just a few times a year. He or she may try to stop taking the drug(s) but fail even though the person knows that the drug is affecting his or her own health, family life, relationships, and work. He or she may even realize that with continued use of the drug, he or she is putting him or her self in danger, especially when the person gets behind the wheel of a car under the influence of drugs.   Substance Abuse A person may continue to take drugs because his or her body does not build up tolerance nor go through withdrawal. The person will continue using drugs despite their harmful consequences.   Withdrawal: Withdrawal is a state of acute physical and psychological pain with symptoms ranging from mild to life-threatening. A person suffers from withdrawal when he or she reduces or stops using a drug.