Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
The Diagnostic and Statistical Manual of Mental Disorders (DSM) is an American handbook for mental health professionals that lists different categories of mental disorders and the criteria for diagnosing them, according to the publishing organization the American Psychiatric Association. It is used worldwide by clinicians and researchers as well as insurance companies, pharmaceutical companies and policy makers. The present version of DSM-IV-TR doesn’t use the word addiction at all. Instead it has a section about Substance dependence
- "When an individual persists in use of alcohol or other drugs despite problems related to use of the substance, substance dependence may be diagnosed. Compulsive and repetitive use may result in tolerance to the effect of the drug and withdrawal symptoms when use is reduced or stopped. This, along with Substance Abuse are considered Substance Use Disorders...." 
Substance dependence can be diagnosed with physiological dependence, evidence of tolerance or withdrawal, or without physiological dependence.
The related concept drug addiction has many different definitions. Some writers give in fact drug addiction the same meaning as substance dependence, others for example provides drug addiction a narrower meaning which excludes drugs without evidence of tolerance or withdrawal symptoms.