Polysubstance Dependence involves repeated use of at least three groups of substances during a 12-month period (excluding caffeine and nicotine), with none of the substance predominating.

Substance dependence is characterized by a cluster of cognitive, behavioral and physiological symptoms that indicates the person continues use of the substance in spite of significant substance related difficulties. The pattern of repeated self-administration usually results in tolerance, withdrawal and compulsive drug-taking behavior. Substance dependence is characterized by three or more of the following symptoms occurring at any time in the same 12 months period:

• Tolerance
• Withdrawal
• Taking the substance in larger amounts and over a longer period than was intended
• Desire to reduce substance use
• Spending a great deal of time in obtaining the substance
• Impairment in social
• Interpersonal or occupational functioning because of substance use
• Continued use of the substance despite physical or psychological problems associated with drug use

Substance abuse involves a maladaptive pattern of use resulting in recurrent and significant problems. One or more of the following occurs withing a 12-month period:

• Failure to fulfill role obligations
• Repeated use in physically hazardous situations
• Multiple legal problems
• Recurrent social and interpersonal problem