Persecutory delusions, schizotypy and disruptions to theory of mind

• Main Author: Williams, Claire
• Published: University College London (University of London) 2006
• Subjects: 616.89
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.722215

Frith (1992) proposed that disruptions to 'theory of mind' (Premack and Woodruff, 1978) or 'mentalising' could explain the signs and symptoms of schizophrenia. For Frith, persecutory delusions represent a disorder in monitoring the thoughts and intentions of others. Following Frith's (1992) model, disruptions to theory of mind have been included in the main cognitive models of persecutory delusions. This review will first outline Frith's neuropsychological model of schizophrenia. It will then summarise the role theory of mind disruptions are given by the main cognitive models of persecutory delusions (Bentall, Corcoran, Howard, Blackwell and Kinderman, 2001 Freeman, Garety, Kuipers, Fowler and Bebbington, 2002) and the cognitive model of positive symptoms (Garety, Kuipers, Fowler, Freeman and Bebbington, 2001). The empirical evidence for such a disruption is then reviewed from studies with a patient population and studies with a non-patient population who vary of the dimension of schizotypy. It is concluded that empirical studies to date have mostly employed traditional theory of mind tests that are designed to assess simple theory of mind deficits such as those seen in autism or the behavioural signs of schizophrenia (Frith, 1992). It is suggested that traditional tests are not able to detect the subtle disruptions to theory of mind related to persecutory delusions. The concepts of 'hyper-ToM' (Abu-Akel and Bailey, 2000) and 'over-mentalising' are discussed and it is suggested that future research should focus on the development of tests which are able to detect 'hyper-ToM' or 'over-mentalising' in patients with persecutory delusions or non-clinical populations who are high on delusional ideation and paranoia.