Neuropsychiatric Model of Addiction Simplified.

While substance experimentation typically begins in adolescence, substance use disorders (SUDs) usually develop in late teens or early adulthood, often in individuals who are vulnerable because of biological and socioeconomic risk factors. Severe SUDs-synonymous with addiction-involve changes in limbic and prefrontal brain areas after chronic drug exposure. These changes involve learned associations between drug reward and cues that trigger the anticipation of that reward (known as incentive salience), as well as heightened dysphoria during withdrawal and weakened prefrontal circuits needed for inhibiting habitual responses.