Violent crime and dimensions of delusion: a comparative study of criminal and noncriminal delusional patients.

Some aspects of delusional disorders appear to be related to the occurrence of violent crime. A retrospective study was conducted comparing two groups of 30 psychotic, delusional patients. The study group consisted of delusional patients imprisoned in a high-security forensic hospital in the state of São Paulo, Brazil, and the patients in the comparative group were enrolled in common psychiatric wards. The PANSS (Positive and Negative Syndrome Scale), the MINI (Mini International Neuropsychiatric Interview), and the MMDAS (MacArthur-Maudsley Delusion Assessment Schedule) scales were used. Regarding the dimensions of delusions, the study group had lower scores in two categories: refraining from acting because of belief, and negative affect. Delusions that induce inhibition of actions apparently also reduce the potential for violent acts and, contrary to current beliefs, delusional patients who are frightened or who have other negative affects associated with delusional ideas appear to commit fewer violent acts. Intrinsic factors inherent in some dimensions of delusion may be relevant in the occurrence of violent crimes committed by psychotic patients.