Substance Use Disorder: What Is It?

Substance-use disorder comprises a wide variety of behaviors that include, but are not limited to, addiction, excessive usage, and dangerous substance-induced behavior. Diagnosis is based on a pattern of behaviors that include an inability to control substance use, impairment of functioning at school, home or work, interpersonal problems caused or exacerbated by the substance use, and risky or hazardous use of the substance. Tolerance to the substance, demonstrated by an increased dose needed to achieve the desired effect, is another criterion.