The first antipsychotic medication was discovered by a French naval surgeon named Henri Laborit. Dr. Laborit had little interest in psychiatry, but was avidly seeking a way to better treat wounded soldiers who were in shock. In June of 1951, he obtained a medication from the French Pharmaceutical firm Rhone-Poulenc that was billed as effective in “potentiating” anesthetic agents used during surgery. He found it quite helpful, but noted a strange sense of psychological apathy as a side effect. The compound, a phenothiazine dubbed “4560 RP”, was later named “chlorpromazine”, and Laborit persuaded some psychiatrist colleagues to try it on their patients. The first patient to receive it was Jacques L, a 24 year old in the midst of a manic episode., on January 19, 1952. Soon, news of the drug had spread throughout France, and the following year American psychiatrists discovered it.
Source: Edward Shorter, A History of Psychiatry, New York: John Wiley and Sons, Inc., 1997.