The American Psychiatric Association says that a person is dependent if their pattern of substance use leads to clinically significant impairment or distress shown by three or more of the following in a 12-month period:
1. Tolerance as defined by any of the following:
2. Withdrawal, as manifested by either of the following:
3. The substance is often taken in larger amounts or over a longer period than was intended (loss of control)
4. There is a persistent desire or unsuccessful efforts to cut down or control substance use (loss of control)
5. A great deal of time is spent in activities necessary to obtain the substance, use the substance or recover from its effects (preoccupation)
6. Important social, occupational or recreational activities are given up or reduced because of substance use (continuation despite adverse consequences)
7. The substance use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by the substance (adverse consequences)