Folie à familie: a cognitive study of delusional beliefs

JASPERS (1913/1959) initially differentiated between primary and secondary delusions. Whereas primary delusions were conceptualized as changes in experience or mood that were not comprehendible by the individual, secondary delusions were those beliefs that possessed an understandable cognitive content (Walker 1991). Cognitive theories have recently focused on these delusional beliefs and, to varying degrees, conceptualized them as the products of attempted explanations of anomalous experiences (Bentall et al. 1994). For example, an individual experiencing depersonalization may attribute this experience to witches controlling his or her body, and will thereafter interpret perceptual experiences that are consistent with this belief. In this sense, Maher (1988) has conceptualized delusions as normal cognitions that account for abnormal perceptual experiences.