Hyper-Theory-of-Mind in Children with Psychotic Experiences

et al. (2014) Hyper-Theory-of-Mind in Children with Psychotic Experiences. PLoS ONE 9(11): e113082. doi:10.1371/journal.pone.0113082 Hyper-Theory-of-Mind in Children with Psychotic Experiences Lars Clemmensen 0 Jim van Os 0 Anne Mette Skovgaard 0 Mette Vaever 0 Els M. A. Blijd-Hoogewys 0 Agna A. Bartels-Velthuis 0 Pia Jeppesen 0 Nori Takei, United (Osaka U, Kanazawa U, Hamamatsu U Sch Med, Chiba U and Fukui U) Graduate School of Child Development, Japan 0 1 Child and Adolescent Mental Health Center, Mental Health Services, the Capital Region of Denmark , Copenhagen , Denmark , 2 Department of Psychiatry and Psychology, Maastricht University Medical Centre , Maastricht , The Netherlands , 3 Department of Public Health, University of Copenhagen , Copenhagen , Denmark , 4 Department of Psychology, University of Copenhagen, Copenhagen, Denmark , 5 INTER-PSY Groningen, Groningen , The Netherlands , 6 University of Groningen, University Medical Center Groningen, University Center for Psychiatry Groningen , Groningen Triadegebouw , The Netherlands Background: Alterations in Theory-of-Mind (ToM) are associated with psychotic disorder. In addition, studies in children have documented that alterations in ToM are associated with Psychotic Experiences (PE). Our aim was to examine associations between an exaggerated type of ToM (HyperToM) and PE in children. Children with this type of alteration in ToM infer mental states when none are obviously suggested, and predict behaviour on the basis of these erroneous beliefs. Individuals with HyperToM do not appear to have a conceptual deficit (i.e. lack of representational abilities), but rather they apply their theory of the minds of others in an incorrect or biased way. Method: Hypotheses were tested in two studies with two independent samples: (i) a general population sample of 1630 Danish children aged 11-12 years, (ii) a population-based sample of 259 Dutch children aged 12-13 years, pertaining to a case-control sampling frame of children with auditory verbal hallucinations. Multinomial regression analyses were carried out to investigate the associations between PE and ToM and HyperToM respectively. Analyses were adjusted for gender and proxy measures of general intelligence. Results: Low ToM score was significantly associated with PE in sample I (OR = 1.6 95%CI 1.1-2.3 x2(4) = 12.42 p = 0.010), but not in sample II (OR = 0.9 95%CI 0.5-1.8 x2(3) = 7.13 p = 0.816). HyperToM was significantly associated with PE both in sample I (OR = 1.8, 95%CI 1.2-2.7 x2(3) = 10.11 p = 0.006) and II (OR = 4.6, 95%CI 1.3-16.2 x2(2) = 7.56 p = 0.018). HyperToM was associated particularly with paranoid delusions in both sample I (OR = 2.0, 95%CI: 1.1-3.7% x2(4) = 9.93 p = 0.021) and II (OR = 6.2 95%CI: 1.7-23.6% x2(4) = 9.90 p = 0.044). Conclusion: Specific alterations in ToM may be associated with specific types of psychotic experiences. HyperToM may index risk for developing psychosis and paranoid delusions in particular. - Data Availability: The authors confirm that all data underlying the findings are fully available without restriction. All relevant data is available through Dryad (DOI: 10.5061/dryad.8dq25). Funding: AMS recieved funding for CCC2000 from Tryg Foundation (J.nr. 7-10-0189 and J. nr. 7-11-0341) (http://www.trygfonden.dk/Om-TrygFonden/In-English), and Lundbeck Foundation (j. nr. R54-A5843) (http://www.lundbeck.com/global/corporate-responsib/stakeholders/the-lundbeck-foundation). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: INTER-PSY is an outpatient clinic for mental health care services, which employs 160 professionals (psychiatrist, psychologists and social workers). Els Blijd-Hoogewys, Ph.D., is a certified clinical psychologist and psychotherapist working at this centre. She is director of the Autism Team. There are no competing interests, financial gains, patents, marketed products, etc. involved concerning the topic of this article. This does not alter the authors adherence to PLOS ONE Editorial policies and criteria. A systematic review [1] documents that alterations in Theoryof-Mind (ToM) are found in people at familial risk of psychotic disorder. In addition, longitudinal studies propose that individuals who later develop schizophrenia, show ToM deficits in childhood [1]. Therefore, altered ToM may constitute an underlying, partly genetically mediated [1,2], indicator of vulnerability for development of psychosis and schizophrenia [1,3]. Recent studies in adult samples of both patients and individuals at familial risk of psychosis [49] have found altered ToM abilities to be associated not only with a diagnosis of schizophrenia but also, and more specifically, with specific psychotic symptoms [1012]. However, these findings are diverging with regard to which ToM deficits are associated with which symptoms. Hallucinations, delusions and other psychotic symptoms in the absence of diagnosable psychotic illness occur frequently in the general population. Recent meta-analyses found a median prevalence of such non-clinical Psychotic Experiences (PE) of around 7% in the general population of all ages [13], and around 17% in the subgroup of children aged 912 years [14]. PE are usually transitory, but longitudinal cohort studies have shown an association with later development of psychotic illness, indicating that PE may index psychometric risk for psychotic disorder [13 16]. PE and alterations in ToM are associated with each other [9,17], but studies have for the most part been carried out in adult samples, and only three studies have examined these associations in non-clinical samples of children [1820]. In two of the studies involving children, associations were found between current PE and poor ToM [18,19]. In the third study, the overall score of ToM did not differentiate between children with and without PE [20]. However, in this study, lower ToM scores mediated the association between a lifetime history of auditory verbal hallucinations (AVH) and presence of delusions at age 1213 years, i.e. children with AVH had a higher likelihood of forming secondary delusional ideation given lower ToM skills. This is in line with the other longitudinal study [18] finding that poor ToM at age 5 years predicted PE at age 12 years. The divergence in findings regarding which symptoms of psychosis are related to ToM may be related to methodological dissimilarities across studies, e.g regarding the measurement of ToM and the classification of symptom clusters [1,21,22]. A more basic explanation may involve the heterogeneity and multidimensionality of ToM as a construct [23]. It has been suggested that deficits may occur in (i) the representational abilities (i.e. a conceptual deficit), so that an individual is unaware that others can hold a false belief about a state of affairs [24,25], as well as in (ii) application abilities (i.e. defi (...truncated)