Three or more of these criteria within the same 12-month period defines dependence:

1. Substance often taken in larger amounts or over a longer period of time than was intended.
2. Persistent desire or unsuccessful efforts to cut down or control substance use.
3. A great deal of time spent in activities necessary to get the substance, use the substance, or recover from its effects.
4. Frequent intoxication or withdrawal symptoms when expected to fulfill major role obligations at work, school, or home.
5. Important social, occupational, or recreational activities given up or reduced because of substance abuse.
6. Continued substance use despite knowledge of having a persistent or recurrent psychological or physical problem that is likely caused or exacerbated by the use of the substance.
7. Tolerance, as defined by either:
   
   1. Marked tolerance (need for markedly increased amounts of the substance).
   2. Markedly diminished effect with continued use of the same amount of the substance.
8. Withdrawal, as manifested by either of the following:
   
   1. Characteristic withdrawal symptoms.
   2. Substance often taken to relieve or avoid withdrawal symptoms.

Substance abuse is defined as (where the criteria for dependence have not been met) meeting one or more of the following criteria:

1. Continued use despite knowledge of having persistent or recurrent social problems caused by or exacerbated by the effects of the substance.
2. Recurrent substance use in situations in which use is physically hazardous.
3. Recurrent, substance-related legal problems.
4. Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home.