Repression is the basic defense mechanism, proposed by Freud, that banishes anxiety-arousing thoughts, feelings, and memories from conscious awareness. The material is not erased; it is kept out of awareness and may influence behavior indirectly.

In classical psychoanalytic theory, repression is motivated and automatic. Unacceptable wishes or traumatic memories are pushed into the unconscious, where they remain active and may return in disguised form as symptoms, dreams, or slips. Empirical support for repression as a special, motivated process remains controversial. Many researchers prefer to speak of ordinary forgetting, avoidance, or retrieval failure rather than a distinct repressive mechanism.

Laboratory studies of directed forgetting and of emotional memory show that people can intentionally or automatically reduce the accessibility of unwanted material. Clinical observations continue to document cases in which distressing memories are unavailable for long periods and later return. The concept remains influential in psychotherapy even as its precise mechanisms are debated.

When anxiety-laden material is kept outside awareness, the process is traditionally called repression.