Shakespeare's Hamlet (1600-1601) inspired innovative psychological and psychoanalytic studies during the XX^th century, related to the Oedipus Complex and the theme of desire (S. Freud, J. Lacan).

Hamlet , with his unique ability to speculate and incapacity to make decisions, became the emblem of existential restlessness and inner conflict that precedes choice ; as a dark and gloomy soul, his melancholy had a very strong appeal in studies of the formation of identity and melancholy-depression seen as the outcome of expulsion from a symbolic order.

Hamlet was also read as the tragedy that foreshadows the notion of moral conscience (Act III) widely investigated and theorized in the XX^th century in the context of studies between consciousness and societies developed in the fields of neurobiology and ethics.

The themes of negative emotions (sadness, hatred, melancholy) present in Hamiet's tragedy - the aspects of desire and psychoanalytic change to which Hamlet's melancholy personality made a considerable contribution - are first introduced, and then analysed in more depth through some works of S. Freud ( Mourning and Melancholy , 1917) and J. Lacan ( Seminary VI. Desire and its Interpretation , 1958-1959).