Loneliness is experienced by nearly everyone, although its frequency and intensity vary widely. Existential loneliness may derive from the universal experience of separation from the mother in leaving the womb; it is an intrinsic and organic reality of each life. The other kind of loneliness comes from self-rejection and self-alienation from society and appears to be related to depression. The latter may lead to aberrant or self-destructive behavior such as drug abuse, but rarely to aggressive or anti-social behavior. There is some evidence that the ability to deal with loneliness is related to the experience of having been alone as a child in the presence of one parent, usually the mother. Without this experience, the capacity to confront loneliness is arrested; with it, a supportive environment is built into the personality. For the psychotherapist, each aspect of loneliness offers a special challenge. Psychoanalysis, behavior modification, and cognitive psychology may be used by therapists to help their patients cope with loneliness. The goal of therapy is to provide options for patients experiencing unwanted, prolonged loneliness. (Author/ABL)