The first patient to receive a modern antidepressant was Paula J. F., a Swiss woman admitted to the Munsterlingen asylum with depression. Her psychiatrist, Roland Kuhn, was a prominant Swiss psychoanalyst of his day, but also had an interest in organic psychiatry, having been one of the pioneers in the use of EEGs. At the time, antihistamines were being tested for a variety of psychiatric uses, from simple sedation to antipsychotic properties. Dr Kuhn prescribed Paula J. F. an antihistamine created by Geigy known as “G22355” on January 12, 1956. Six days after her first dose, Paula was transformed. Kuhn then treated 40 more patients with the compound, and described the responses as “absolutely incredible.” The compound was later named “imipramine” and became the gold standard of antidepressant treatment for the next 35 years.

Source: Edward Shorter, A History of Psychiatry, New York: John Wiley and Sons, Inc., 1997