Drug addiction - is defined as a state of acute or chronic poisoning caused by constant process of taking prescribed or illicit drug(s). The drug can be taken in its natural or synthetic form. The characteristics of drug addiction are as follow: 1. Irresistible compulsion to acquire and then the need to take the drug. 2. Tendency to increase the dose of the drug. 3. Physical and sometimes psychological dependency on the effect of the drug or medication. Definition created by WHO Experts Committee on Drug Dependence