[Psychotherapy of delusions].

Psychotherapy of delusion is usually considered far from promising. However, patients with delusional problems require some of psychotherapy if they fail to respond to pharmacological treatment, particularly if their behaviour and wellbeing are severely disturbed. Case reports indicate that at least delusional social behaviour, but also general cognitive styles, can be influenced outside of delusional perception and the delusional work of systematization. Diagnostic assessment for psychotherapy of deluded patients should clarify: the affective charge of the delusion; the degree of fixation; and its compensatory function for impeding disorganization. The expressive function of the delusion may help the therapist to pay attention to the patient's most important and unresolved life themes, even if they cannot be addressed at the beginning of the therapy. In the acute phase this knowledge can help to disactualize the theme; in the post-acute phase it can help to reflect on the further destiny of the blocked development expressed in the theme, be it by grief or by promoting it to more adequate striving. Based on those theories of delusion which have a practical impact and illustrated by case vignettes, proposals are made on how to deal psychotherapeutically with the pre-predicative statement of delusional belief, how to support disactualization of the delusional theme, how to help the patient with self-presentation, and how to support more flexible decentered cognitive styles.