Psychoanalytic theory is the theory of personality organization and the dynamics of personality development that guides
Psychoanalytic and psychoanalytical are used in English. The latter is the older term, and at first simply meant 'relating to the analysis of the human psyche'. But with the emergence of psychoanalysis as a distinct clinical practice, both terms came to describe that. Although both are still used, today, the normal adjective is psychoanalytic.
Psychoanalysis is defined in the Oxford English Dictionary as
A therapeutic method, originated by Sigmund Freud, for treating mental disorders by investigating the interaction of conscious and unconscious elements in the patient's mind and bringing repressed fears and conflicts into the conscious mind, using techniques such as dream interpretation and free association. Also: a system of psychological theory associated with this method.
Through the scope of a psychoanalytic lens, humans are described as having sexual and aggressive drives. Psychoanalytic theorists believe that human behavior is deterministic. It is governed by irrational forces, and the unconscious, as well as instinctual and biological drives. Due to this deterministic nature, psychoanalytic theorists do not believe in free will.