Nowadays resentment is important in Health Psychology within the concept of AHA Syndrome, Anger-Hostility-Aggression, originally proposed by Spielberger, as risk factor in some organic disorders, especially cardiovascular ones. In Clinical Psychology this is not the case, especially in Cognitive-Behavioral Psychology, where aggressiveness due to hate, or resentment, is seldom seen as a main characteristic of psychopathological disorders. Aggressiveness due to hate, or resentment, is formed by unresolved indignity and its later defensive dynamic. The resentful person lives in a world of falsehood in order not to feel indignity, or to express his or her hate through covert aggressions to himself or herself, or to
others. This aggressiveness due to hate can become an interpersonal style that transforms the person’s life into one of the diverse Millon´s personality disorders, which positively consider resentment as one of their main characteristics.