A complex is a core pattern of emotions, memories, perceptions, and wishes in the personal unconscious organized around a common theme, such as power or status. Primarily a psychoanalytic term, it is found extensively in the works of Carl Jung and Sigmund Freud.

An example of a complex would be as follows: if you had a leg amputated when you were a child, this would influence your life in profound ways, even if you overcame the physical handicap. You may have many thoughts, emotions, memories, feelings of inferiority, triumphs, bitterness and determinations centering on that one aspect of your life. If these thoughts were troubling and pervasive, Jung might say you had a complex about the leg.

Complex existence is widely agreed upon in the area of depth psychology, a branch of psychology that asserts the most significant parts of your personality are derived from your unconscious. It is a way of mapping the psyche, and are crucial theoretical items in therapy. Complexes are believed by Carl Jung and Sigmund Freud to influence an individual's attitude and behavior.