clinical guidelines for a definite diagnosis of “dependence” require that three or more of the following six characteristic features be experienced or exhibited: A strong desire or sense of compulsion to take the drug; Difficulties in controlling drug-taking behaviour in terms of its onset, termination, or levels of use; A physiological withdrawal state when drug use is stopped or reduced, as evidenced by: the characteristic withdrawal syndrome for the substance; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms; Evidence of tolerance, such that increased doses of the drug are required in order to achieve effects originally produced by lower doses; Progressive neglect of alternative pleasures or interests because of drug use, increased amount of time necessary to obtain or take the drug or to recover from its effects; Persisting with drug use despite clear evidence of overtly harmful consequences, such as harm to the liver, depressive mood states or impairment of cognitive functioning. From Wikipedia, the free encyclopedia