Psychoanalysis (from Greek: ψυχή, psykhḗ, 'soul' + ἀνάλυσις, análysis, 'investigate') is a set of theories and therapeutic techniques that deal in part with the unconscious mind, and which together form a method of treatment for mental disorders. The discipline was established in the early 1890s by Austrian neurologist Sigmund Freud, who retained the term psychoanalysis for his own school of thought. Freud's work stems partly from the clinical work of Josef Breuer and others. Psychoanalysis was later developed in different directions, mostly by students of Freud, such as Alfred Adler and his collaborator, Carl Gustav Jung, as well as by neo-Freudian thinkers, such as Erich Fromm, Karen Horney, and Harry Stack Sullivan.

Psychoanalysis is a controversial discipline. Its validity as a science is contested, and its critics allege that it is a pseudoscience. Nonetheless, it retains a salient influence within psychiatry. Psychoanalytic concepts are also widely used outside the therapeutic arena, in areas such as psychoanalytic literary criticism, as well as in the analysis of film, fairy tales, philosophical perspectives as Freudo-Marxism and other cultural phenomena.