* Anna O a patient of Dr. Joseph Breuer (Freud's mentor and friend) from 1800 to 1882 suffered from hysteria.
* In 1895 Breuer and his assistant, Sigmund Freud, wrote a book, Studies on Hysteria. In it they explained their theory: Every hysteria is the result of a traumatic experience, one that cannot be integrated into the person's understanding of the world. The publication establishes Freud as “the father of psychoanalysis.”
* By 1896 Freud had found the key to his own system, naming it psychoanalysis. In it he had replaced hypnosis with "free association."
* In 1900 Freud published his first major work, The Interpretation of Dreams, which established the importance of psychoanalytical movement.
* In 1902 Freud founded the Psychological Wednesday Society, later transformed into the Vienna Psychoanalytic Society. As the organization grew, Freud established an inner circle of devoted followers, the so-called "Committee" (including Sàndor Ferenczi, and Hanns Sachs (standing) Otto Rank, Karl Abraham, Max Eitingon, and Ernest Jones).
* Freud and his colleagues came to Massachusetts in 1909 to lecture on their new methods of understanding mental illness. Those in attendance included some of the country's most important intellectual figures, such as William James, Franz Boas, and Adolf Meyer.
* In the years following the visit to the United States, the International Psychoanalytic Association was founded. Freud designated Carl Jung as his successor to lead the Association, and chapters were created in major cities in Europe and elsewhere. Regular meetings or congresses were held to discuss the theory, therapy, and cultural applications of the new discipline.
* Jung's study on schizophrenia, The Psychology of Dementia Praecox, led him into collaboration with Sigmund Freud.
* Jung's close collaboration with Freud lasted until 1913. Jung had become increasingly critical of Freud's exclusively sexual definition