• Psychology Timeline : 1800's | 1900's | 2000's

1900s

1900

• Clifford Beers has a nervous breakdown, attempts suicide, and is institionalized. There, he is diagnosed as manic-depressive.
• Carl Jung receives his degree in psychiatry from the University of Basel.
• Erich Fromm is born.
• Sigmund Freud publishes The Interpretation of Dreams, the first outline of some of his most well-known ideas, including: the Id, Ego, Superego, and the Oedipus Complex.

1901

• British Psychological Society is formed.
• Mary Whiton Calkins publishes Introduction to Psychology

1904

• The Psychopathology of Everyday Life by Sigmund Freud is published.

1905

• A Case of Hysteria by Sigmund Freud is published.
• Three Essays on the Theory of Sexuality by Sigmund Freud is published.

1906

• Ivan Pavlov publishes his research on classical conditioning.

1907

• Clifford Beers publishes A Mind That Found Itself.

1908

• Nathan Ackerman is born.

1910s

1910

• Max Wertheimer (1880–1943) publishes an influential article on Gestalt psychology.

1911

• Alfred Binet dies.

1920s

1930s

1930

• Mary Whiton Calkins dies.

1939

• Sigmund Freud dies, controversially. During his life, Freud created Psychoanalysis, a theory of the unconscious including three parts, the Id, Ego and Superego; and generally pissed alot of people off.

1940s

1941

• Kurt Koffka, one of the founders of Gestalt psychology, dies.

1943

• Clifford Beers dies.

1944

• James McKeen Cattell was born. He would go on to become the first professor of psychology in America.

1950s

1952

• The first edition of the DSM is published.

1960s

1961

• Carl Jung dies.

1970s

1971

• Nathan Ackerman dies.

1980s

1980

• DSM-III is published.
• Erich Fromm dies.

1990s

1994

• DSM-IV is published.
• Francis Crick publishes his book on consciousness, "The Astonishing Hypothesis"