Impairment in social and occupational functioning resulting from the pathological and “compulsive” use of a substance. The concept is closely related to the definition of substance dependence, which has similar symptoms of impairment but may also include evidence of physiological tolerance or withdrawal. Typical symptoms of substance abuse include inability to fulfill major role obligations at work, school, or home; recurrent use of the substance in situations in which such use is physically hazardous; substance-related legal problems; and continued use even though it causes or exaggerates interpersonal problems.