The Truth about what drug addiction entails
Mental Health Professionals uses the DSM IV when working with patients in order to better understand their illness and potential treatment. Most importantly it helps to identify what the criteria is for diagnosing someone as being addicted to a substance.
Definition of Drug Abuse: Drug abuse, is the continuous use of a drug in which the user consumes the substance in amounts or with methods which are harmful to themselves. (wikipedia.org/wiki/Substance_abuse)