Theory of mind in individuals with paranoid schizophrenia

Individuals with schizophrenia show deficits in theory of mind (ToM), however the nature of these deficits in individuals with paranoid symptoms is unclear. This study examined whether ToM ability in individuals with paranoid schizophrenia varied according to the emotional valence of items within ToM tasks. Eight participants with a diagnosis of paranoid schizophrenia (patient group) and eight healthy controls completed two ToM tasks, the revised Eyes Test and a newly developed mental state reasoning task (New ToM Measure). Controls were significantly more accurate than the patient group on both tasks (revised Eyes Test: t (14) = 4.48, p = .001, d = 2.24, New ToM Measure: t (14) = 3.63, p = .003, d = 1.82). There was evidence of a trend for a mediating role of emotional valence in the patient group on the revised Eyes Test, although contrary to the study’s hypothesis, patients were more accurate on positive items than threat items (t (7) = 2.19, p = .07, d = 1.01). There was no evidence of a mediating role of emotional valence on the New ToM Measure. This study provides further evidence of ToM deficits in individuals with schizophrenia. The mixed evidence for the mediating role of emotional valence is discussed in relation to existing literature and the study’s limitations