The widely abused amphetamine analog 3,4‐methylenecdioxymethamphetamine (MDMA, also called “ecstasy”) induces hallucination and psychostimulation, as well as long‐term neuropsychiatric behaviors such as panic and psychosis. In rodents and monkeys, MDMA is cytotoxic to serotonergic neurons, but this is less clear with humans. Herein, MDMA was cytotoxic to human serotonergic JAR cells; it altered...