Designer drugs, marketed as 'legal highs,' include substituted cathinones (e.g., mephedrone, methylone, MDPV), synthetic cannabinoids (e.g., Spice), and synthetic hallucinogens (e.g., 25I-NBOMe). Their availability changes rapidly to evade legal controls and detection. Young adults are the main users, with growing use in the military. Acute toxicity frequently causes severe psychiatric and medical effects such as anxiety, agitation, psychosis, and tachycardia, and deaths have been reported for each drug type. Clinicians should consider these drugs when evaluating substance use in young adults or patients with acute neuropsychiatric symptoms. Treatment of acute intoxication is supportive, while long-term treatment of designer drug use disorder lacks evidence-based guidance.
Methamphetamine and MDMA, despite chemical similarities, produce both overlapping and distinct effects in the same individuals. In a residential study with 11 adult volunteers, both drugs acutely increased cardiovascular measures and positive subjective effects while decreasing food intake. Participants had difficulty distinguishing between the drugs. Methamphetamine improved cognitive performance and disrupted sleep, whereas MDMA increased negative subjective-effect ratings. Few residual effects were noted for either drug. These differences may help explain the drugs' differing public perception and abuse potential, though recreational route of administration could also account for many attributed effects.