Physical dependence on drugs or alcohol is also a part of chemical dependency and often needs a managed detoxification program for successful removal of the substances from your body. It is similar to that of substance dependence, a compulsive or chronic need for, or an active addiction to, alcohol or drugs.
Some people uses recreational or prescription drugs without ever experiencing addiction and its negative consequences, some drugs of abuse have a mechanism of action similar to that of drugs used as psychotherapeutic agents. Most experts feel that addiction is a brain disease. The brain changes associated with addiction can be treated and reversed through therapy, medication, exercise, and other treatments.
Many substances, such as alcohol, tranquilizers, opiates, and stimulants, over time also can produce a phenomenon known as tolerance, where you must use a larger amount of the drug to produce the same level of intoxication, This result in acute pharmacological disturbances like flushing, unsteady gait, euphoria, increased activity, slurred speech and impaired judgment that is caused by a chemical substance.