Repression is a defense mechanism in psychology where people unconsciously block unpleasant emotions, thoughts, memories, and impulses from their conscious mind. It is a key concept of psychoanalysis, where it is understood as a defense mechanism that "ensures that what is unacceptable to the conscious mind, and would if recalled arouse anxiety, is prevented from entering into it"). Repression is thought to give rise to anxiety and to neurotic symptoms, which begin when a forbidden drive or impulse threatens to enter the conscious mind.

Repression is often associated with sexual or aggressive urges or painful childhood memories, and these unwanted mental contents are pushed into the unconscious mind. Psychoanalysis seeks to uncover repressed memories and feelings through free association as well as to examine the repressed wishes released in dreams.

Repression may sometimes be confused with suppression, but there is a distinction. “Suppression” refers to a person consciously pushing away distressing thoughts in order to focus on reality and activities of daily life. Repression, on the other hand, is unconscious blanking of distressing memories by the brain, a way to cope with painful emotions.

Examples of repression include slips of the tongue, known as “Freudian slips,” when people accidentally say something when they want to say something else, and repressed memories of childhood abuse.

In summary, repression is a defense mechanism in psychology where people unconsciously block unpleasant emotions, thoughts, memories, and impulses from their conscious mind. It is often associated with sexual or aggressive urges or painful childhood memories, and it is thought to give rise to anxiety and neurotic symptoms. Repression is different from suppression, which is a conscious effort to push away distressing thoughts.