What did Freud's psychoanalysis claim, and how is it seen today?

Psychoanalysis is a set of theories and a talk therapy, established in the early 1890s by Sigmund Freud. Its central claim is that unconscious processes, mental activity we are not aware of, largely determine what we think, feel and do. Freud called this the third insult to mankind, after Copernicus (the Earth revolves around the Sun) and Darwin (humans evolved from apes).

The method began with a patient. Bertha Pappenheim, known in print as "Anna O.", was the shared patient of Freud and his colleague Josef Breuer, and she herself dubbed the treatment the "talking cure". Their 1895 book, Studies on Hysteria, is generally seen as the birth of psychoanalysis. Freud then dropped hypnosis, because its results were inconsistent, and asked patients to say whatever came to mind without censorship: free association. In the classic setting the patient lies on a couch with the analyst sitting out of sight behind. Freud also argued that dreams carry symbolic meanings, and therapy aims to induce transference, in which the patient projects onto the analyst the parental figures internalised in childhood.

The aim, in Freud's words, was "Where id was, there ego shall be".

How is it seen now? Wikipedia calls psychoanalysis controversial from the outset, while its influence on psychology and psychiatry is undisputed. Philosopher Karl Popper argued it is a pseudoscience because its claims cannot be refuted. Adolf Grünbaum replied that the theories can be tested but that their causal claims are unsupported by clinical evidence. Even the Anna O. case is contested: some accuse Freud of fabrication, and others think she had medical illnesses rather than hysteria.

On treatment results, the evidence is mixed. A 2012 meta-analysis of long-term psychodynamic therapy found a modest effect and called the evidence limited and at best conflicting, while a 2020 meta-analysis found small but significant benefits over other psychotherapies. The next lessons turn to other schools of therapy.