Out of the night-time and into the day: Ketamine and MDMA as therapies for mental disorders.

An editorial is presented on ketamine and 3,4-methylenedioxymethamphetamine (MDMA) being old drugs with apparent new uses. Topics include focusing on the brain mechanisms of depression in the role of the glutamatergic system; increasing glutamate transmission having toxic brain effects precipitating and perpetuating depression; and considering chemotherapies for cancers and intravenous immunoglobulin for autoimmune disorders.