Although psychiatric medications have been shown to be safe and tolerable in clinical trials and most have been used for years by many thousands of people, some prescription drugs become drugs of abuse. Which medications are most likely to be misused this way? Opiates and benzodiazepines are the classes of medications that are most likely to be abused. Antidepressants, antipsy-chotics, and mood stabilizers are less frequently abused. Data from the U.S. government agency SAMHSA list sedatives, pain relievers, stimulants, and tranquil-izers as the most common candidates for prescription drug abuse. Drugs with a quick onset of action, a tendency to cause euphoric feelings, and a short half-life are more vulnerable to misuse.