[Man at the Frontier of his Being: Scope of the Concept of "Limit Situation" in Psychiatry and Psychotherapy Following Jaspers' Existential Ontology].

BACKGROUND: The existential concept of "limit situation" was proposed by Jaspers as the inevitable threshold of human beings at their ordinary mode of being, namely Dasein, which has to be crossed to reach Existence as the proper mode of being after having transcended an existential challenge. A failure at facing limit situations indicates that they are ineluctable and have to be assumed.

METHOD: The starting point is the analysis of Jaspers' concept of limit situations, both within the antinomic structure of the human condition as well as the duality of being-in-the-world. An attempt is made here to interpret the ontological determination of the limit situation as an ontic one, which could be relevant to psychiatric and psychotherapeutic practice.

RESULTS: The distinction between Dasein and Existence as modes of being is at the basis of Jaspers' existential philosophy. Limit situations cannot be veiled; therefore, they require a transcendence movement of the self in order to overcome enclosures and to reach the mode of being of Existence as authentic selfhood. Jaspers creates an ontological typology of limit situations in which suffering plays a key role. An ontic correspondence for psychiatry and psychotherapy refers to the importance of critical life events, of suicidality, of rigid thought styles and behavior patterns as enclosures; illness is both a limit situation in itself and also its consequence. In anthropological terms, the concepts of existential vulnerability and competence in dealing with limit situations have proved to be rewarding.

DISCUSSION: The ontic correspondence to Jaspers' ontological concept of limit situations suggested by the author makes a fruitful contribution to psychiatry and psychotherapy, because it draws attention to the person-environment fit as a possible predetermined breaking point that could lead to psychopathologically relevant failure. Critical life events understood as relational, as well as existential vulnerability and defense mechanisms biographically illuminated could contribute to an improvement of competence in dealing with limit situations within the psychotherapeutic practice.