1. Freud's study of Mourning and Melancholia provides the psychopathological model for depression. Basing himself upon the views of Abraham regarding the oral sadism which the depressed person wants to inflict upon the lost object. Freud added that the gilt associated with that oral sadistic aggression oppresses the depressed with the weight of his superego. 2. The childhood model for this depression caused by object loss is provided by Melanie Klein, who sees the bad object as a projection of aggressive fantasies, and by Donald Winnicott who regards the excited child as a "worried", although replete. 3. Hence the social importance of the clinical facts of the psychiatry of the very young child: anaclitic depression of separation (René Spitz) or depression by severance of the bonds (John Bowlby). 4. Finally, we must reassess the notion of depression with inferiority (Francis Pasche). It is organised as a disorder of idealisation and must be considered in connection with the feelings of nostalgia of the adolescents in our society.