Substance use disorders are defined as the use of a substance that results in persistent and sometimes pervasive aversive consequences. Substance use disorders have profound economic and public health impacts in the United States. Researchers have identified important biological, psychological, and social factors that predict the development and resolution of substance use disorders. Biological processes related to substance use include physiological reactivity, changes, and adaptations. Psychological processes associated with substance use include conditioning, observational learning, beliefs about substance use, and emotions that cue substance use. Social relationships and environmental stressors also have been found to influence the course of substance use. Diagnostic criteria have been established to define severity and to specify the course of the disorder. Substance use disorders are thought by some to ...