Els M. A. Blijd-Hoogewys

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

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 χ2(4) = 12.42 p = 0.010), but not in sample II (OR = 0.9 95%CI 0.5–1.8 χ2(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 χ2(3) = 10.11 p = 0.006) and II (OR = 4.6, 95%CI 1.3–16.2 χ2(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% χ2(4) = 9.93 p = 0.021) and II (OR = 6.2 95%CI: 1.7–23.6% χ2(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.

Better theory-of-mind skills in children hearing voices mitigate the risk of secondary delusion formation.

Bartels‐Velthuis AA, Blijd‐Hoogewys EMA, van Os J. Better theory‐of‐mind skills in children hearing voices mitigate the risk of secondary delusion formation.

Non-linearities in Theory-of-Mind Development

Research on Theory-of-Mind (ToM) has mainly focused on ages of core ToM development. This article follows a quantitative approach focusing on the level of ToM understanding on a measurement scale, the ToM Storybooks, in 324 typically developing children between 3 and 11 years of age. It deals with the eventual occurrence of developmental non-linearities in ToM functioning, using smoothing techniques, dynamic growth model building and additional indicators, namely moving skewness, moving growth rate changes and moving variability. The ToM sum-scores showed an overall developmental trend that leveled off toward the age of 10 years. Within this overall trend two non-linearities in the group-based change pattern were found: a plateau at the age of around 56 months and a dip at the age of 72–78 months. These temporary regressions in ToM sum-score were accompanied by a decrease in growth rate and variability, and a change in skewness of the ToM data, all suggesting a developmental shift in ToM understanding. The temporary decreases also occurred in the different ToM sub-scores and most clearly so in the core ToM component of beliefs. It was also found that girls had an earlier growth spurt than boys and that the underlying developmental path was more salient in girls than in boys. The consequences of these findings are discussed from various theoretical points of view, with an emphasis on a dynamic systems interpretation of the underlying developmental paths.

A Psychometric Evaluation of the Danish Version of the Theory of Mind Storybook for 8–14 Year-Old Children

Background: Theory-of-Mind (ToM) keeps on developing in late childhood and early adolescence, and the study of ToM development later in childhood had to await the development of sufficiently sensitive tests challenging more mature children. The current study aimed to investigate the psychometric properties of the Danish version of the Theory-of-Mind Storybook Frederik (ToM-Frederik). Methods: We assessed whether ToM-Frederik scores differed between a group of 41 typically developing (TD) children and a group of 33 children with High Functioning Autism Spectrum Disorder (HFASD). A lower mean ToM-Frederik score was expected in the HFASD group. To determine the convergent validity of ToM-Frederik, potential associations with Strange Stories and Animated Triangles (AT) were analyzed. Furthermore, potential associations between ToM-Frederik and the Social Responsiveness Scale (SRS) and between ToM-Frederik and the Social Emotional Evaluation (SEE) Total score were analyzed. Results: A significantly higher ToM-Frederik score was observed in the TD group compared to the HFASD group. Furthermore, the convergent validity of ToM-Frederik as a measure of ToM was supported by significant and positive associations with the Strange Stories and the AT scores in the HFASD group, whereas ToM-Frederik was significantly correlated with Strange Stories, but not with AT in the TD group. ToM-Frederik was not significantly associated with SRS in neither the HFASD nor the TD group. Conclusion: The findings are supportive of ToM-Frederik as a valid indicator of deficits at the group level in children with HFASD between 7 and 14 years of age. Furthermore, the convergent validity is supported.