Theory of mind deficits partly mediate impaired social decision-making in schizophrenia

IMC Seed funded project published results in the Journal BMC Psychiatry

2017.05.10 | Anne-Mette Pedersen

The Seed funded project (2016) "Chinese-Danish transcultural study regarding neural social cognitive subgroups in first episode schizophrenia" has in cooperation with i.a. Chinese Academy of Sciences published an article in BMC Psychiatry.

Background: Using paradigms from game theory, researchers have reported abnormal decision-making in social context in patients with schizophrenia. However, less is known about the underpinnings of the impairment. This study aimed to test whether theory of mind (ToM) deficits and/or neurocognitive dysfunctions mediate impaired social decision-making in patients with schizophrenia.

Methods: We compared thirty-five patients with schizophrenia to thirty-eight matched healthy controls with regard to social decision-making using the mini Ultimatum Game (mini UG), a paradigm from game theory. Additionally, we assessed ToM using the Theory of Mind Picture Stories Task, a mental state attribution task, and assessed neurocognition using the Brief Assessment of Cognition in Schizophrenia. Mediation analyses were performed on the data.

Results: In contrast to the behavioral pattern of healthy controls in the mini UG, the patients with schizophrenia significantly accepted more disadvantageous offers and rejected more advantageous offers, and showed reduced sensitivity to the fairness-related context changes in the mini UG. Impaired ToM and neurocognition were also found in the patients. Mediation analyses indicated that ToM but not neurocognition partially mediated the group differences on the disadvantageous and advantageous offers in the mini UG.

Conclusions: Patients with schizophrenia exhibited impaired social decision-making. This impairment can be partly explained by their ToM deficits rather than neurocognitive deficits. However, the exact nature of the ToM deficits that mediate impaired social decision-making needs to be identified in future.

Theory of mind deficits partly mediate impaired social decision-making in schizophrenia
Liuqing Yang, Peifu Li, Haiying Mao, Huiling Wang, Chang Shu, Vibeke Bliksted and Yuan Zhou

Contact: Associate Professor Vibeke Bliksted, Dept. of Clinical Medicine