Psychoanalytic theory is the theory of personality organization and the dynamics of personality development that guides psychoanalysis, a clinical method for treating psychopathology. First laid out by Sigmund Freud in the late 19th century, psychoanalytic theory has undergone many refinements since his work. Psychoanalytic theory came to full prominence in the last third of the twentieth century as part of the flow of critical discourse regarding psychological treatments after the 1960s, long after Freud’s death in 1939, and its validity is now widely disputed or rejected. Freud had ceased his analysis of the brain and his physiological studies and shifted his focus to the study of the mind and the related psychological attributes making up the mind, and on treatment using free association and the phenomena of transference. His study emphasized the recognition of childhood events that could influence the mental functioning of adults. His examination of the genetic and then the developmental aspects gave the psychoanalytic theory its characteristics. Starting with his publication of The Interpretation of Dreams in 1899, his theories began to gain prominence.