A replication study of JTC bias, genetic liability for psychosis and delusional ideation

• DOI: 10.1017/s0033291720003578
• Publication Date: 2020-10-13T05:48:00Z
• Authors: Cécile Henquet; Jim van Os; Lotta K. Pries; Christian Rausche...; Philippe Delespaul; Gunter Kenis; Jurjen J. Luykx; Bochao D. Lin; Alexander L. Rich...; Berna Akdede; Tolga Binbay; Vesile Altınyazar; Berna Yalınçetin; Güvem Gümüş-Akay; Burçin Cihan; Haldun Soygür; Halis Ulaş; Eylem S. Cankurtaran; Semra U. Kaymak; Marina M. Mihaljevic; Sanja S. Petrovic; Tijana Mirjanic; Miguel Bernardo; Gisela Mezquida; Silvia Amoretti; Julio Bobes; Pilar A. Saiz; Maria P. García-P...; Julio Sanjuan; Eduardo J. Aguilar; Jose L. Santos; Estela Jiménez-López; Manuel Arrojo; Angel Carracedo; Gonzalo López; Javier González-P...; Mara Parellada; Nadja P. Maric; Cem Atbaşoğlu; Alp Ucok; Köksal Alptekin; Meram C. Saka; Celso Arango; Michael O'Donovan; Bart P.F. Rutten; Sinan Gülöksüz
• Keywords: family; Hallucinations; CONVICTION; Decision Making; neuropsychology; Delusions; 03 medical and health sciences; Cognition; 0302 clinical medicine; Bias; Journal Article; Humans; psychosis; VALIDITY; jumping to conclusions; Applied Psychology; 3. Good health; Psychiatry and Mental health; CONTINUUM; Psychotic Disorders; CONCLUSIONS; RELIABILITY; Schizophrenia; delusions; reasoning; Original Article

AbstractBackgroundThis study attempted to replicate whether a bias in probabilistic reasoning, or ‘jumping to conclusions’(JTC) bias is associated with being a sibling of a patient with schizophrenia spectrum disorder; and if so, whether this association is contingent on subthreshold delusional ideation.MethodsData were derived from the EUGEI project, a 25-centre, 15-country effort to study psychosis spectrum disorder. The current analyses included 1261 patients with schizophrenia spectrum disorder, 1282 siblings of patients and 1525 healthy comparison subjects, recruited in Spain (five centres), Turkey (three centres) and Serbia (one centre). The beads task was used to assess JTC bias. Lifetime experience of delusional ideation and hallucinatory experiences was assessed using the Community Assessment of Psychic Experiences. General cognitive abilities were taken into account in the analyses.ResultsJTC bias was positively associated not only with patient status but also with sibling status [adjusted relative risk (aRR) ratio : 4.23 CI 95% 3.46–5.17 for siblings and aRR: 5.07 CI 95% 4.13–6.23 for patients]. The association between JTC bias and sibling status was stronger in those with higher levels of delusional ideation (aRR interaction in siblings: 3.77 CI 95% 1.67–8.51, and in patients: 2.15 CI 95% 0.94–4.92). The association between JTC bias and sibling status was not stronger in those with higher levels of hallucinatory experiences.ConclusionsThese findings replicate earlier findings that JTC bias is associated with familial liability for psychosis and that this is contingent on the degree of delusional ideation but not hallucinations.