| 1885 | Walter R. Miles was born. Miles studied human performance and adaptation to adverse conditions. His work on vision was responsible for the use of red lighting in World War II pilot night mission ready rooms. APA President, 1932; Society of Experimental Psychologists Warren Medal, 1947; American Psychological Foundation Gold Medal, 1962. |
| 1887 | George T. Ladd's book Elements of Physiological Psychology was published. |
| 1946 | The organizing meeting of the Pennsylvania Psychological Association (PPA) was held. During World War II, the state psychological organization, the Pennsylvania Association of Clinical Psychologists (PACP), discontinued its meetings. Morris Viteles, of the University of Pennsylvania, invited members of the 1942 PACP executive committee to meet and revive the association under a new name. The first official meeting of the reconstituted PPA was held on May 20, 1946. |
| 1948 | Lithium was first used in a trial treatment of manic behavior. Australian John F. J. Cade gave lithium citrate to a little wizened man of 51 who had been in a chronic state of excitement for five years. He was amiably restless, dirty, destructive, and interfering. The treatment was surprisingly effective and the patient was discharged on July 9, 1948. |
| 1951 | The drug Phenergan (promethazine; Wyeth) was approved for use by the U.S. Food and Drug Administration. Promethazine is a phenothiazine derivative and is used in clinical settings as an antianxiety agent and as a sedative. It also is prescribed as an antihistamine and motion sickness medication. |
| 1977 | The first informal meeting of the President's Commission on Mental Health was held. President Jimmy Carter created the commission, carrying out a campaign promise of his wife, Rosalynn. Psychologists John Conger and Beverly Long served on the commission. |