DELUSION, THE OVERVALUED IDEA AND RELIGIOUS BELIEFS - A COMPARATIVE-ANALYSIS OF THEIR CHARACTERISTICS

Background The study sought to investigate the form of the delusion in schizophrenia and the overvalued idea in anorexia, employing a range of belief characteristics to discover whether differences could be det ected between them, and how they stood in general relationship to the religious beliefs of normals. Method A belief rating scale was devised with 12 characteristics, and completed by 20 schizophrenics, 20 anore ctics, and 20 normal controls. Comparisons were drawn between populati ons using the Mann-Whitney test, and different types of bel ief we re contrasted within diagnostic groups using each subject as their own co ntrol by repeated-measures MANOVA. Results The schizophrenic delusion was differentiated from the overvalued idea in anorexia by a number of variables, which also served to distinguish both phenomena from relig ious beliefs held by normals. The schizophrenic delusion exhibited man y of the qualities of an initial (or observational) belief when its co ntent suggested that it should manifest those of a derived belief The anorectic overvalued idea, although occasionally an initial belief in terms of its content, was typically held in the form of a derived beli ef. Conclusions A wider range of characteristics is required to define all the differences between delusion and the overvalued idea, and the se have implications for belief modification programmes.