This “Designer Drugs 2.0” issue of Clinical Pharmacology & Therapeutics focuses on novel psychoactive substances, primarily cannabinoids and cathinones, and the repurposing of established psychoactive compounds (e.g., modafinil, psilocybin, lysergic acid diethylamide, and 3,4‐methylenedioxymethamphetamine) that simultaneously offer new pharmacotherapies and pose serious health problems. Novel...