«You fool no one…you thought that you could take me for granted». Delusion: from the fascination of the forensic psychiatrist towards a new criterion for the evaluation of insanity

Abstract

The authors intend to question the common issue in forensic psychiatry that delusions in paranoia clinical cases, determine an evaluation of insanity. In this respect, delusions appear to be, par excellence, the most relevant psychopathological complex on which the insanity of an indicted person is judged. In the first place, it is important to underline that definitory criteria of delusion – even in the modern diagnostic manuals (ICD and DSM) do not drift from the phenomenological matrix established by Jaspers. Nonetheless these criteria, if taken one by one, do not diverge from similar experiences by so called normal individuals. Cognitive sciences seem to demonstrate how cognitive and deductive features of human beings poorly fit canons of classical logic. They would rather show a “confirmational prejudice”, a belief bias, which tends to confirm data on the basis of subjective thoughts and not of premises, employing a lot an imagination criterion, which appears scarcely logic. In particular, the most recent scientific literature on delusions, has investigated some cognitive features of interest. Among them, those, which appear to be the most relevant, are: the “Jumping To Conclusions – JTC” and the “belief inflexibility”. Different studies have concentrated upon relations between variations of anxiety base-line and paranoid thoughts and upon motivational aspects of delusions, as Kraepelin suggested in his classical treatise on paranoia. So, it is necessary to challenge the “certainty” upon which we have based our conviction, so far, that an individual affected by a delusion may be highly considered insane (Italian Penal Code, art. 88 and 89).