A meta-analysis of the associations between theory of mind and neurocognition in schizophrenia

Abstract

Theory of mind (ToM) refers to the ability to infer the mental states of others. ToM is impaired in schizophrenia and these deficits seem to hinder functional recovery. ToM is thus an important, but complex treatment target, supported by several processes. A large number of studies report significant associations between ToM and neurocognition (e.g. memory, attention), but the neurocognitive domains that are most closely linked to ToM remain to be identified. A meta-analysis was conducted to estimate the magnitude of the associations between ToM and neurocognition in people with schizophrenia. Correlations were extracted from the relevant literature, transformed into effect sizes Zr and pooled as weighted means. Focused-tests were employed to test for differences between neurocognitive domains and for differences linked to the characteristics of ToM tasks. Ninety-one studies (N = 5462) were included. Moderate associations emerged between ToM and each neurocognitive domain (Zrs 0.27–0.43), with no significant difference between domains (χ2(8) = 11.89, p = 0.156). Within the domain of executive functions, abstraction showed a stronger association with ToM (χ2(4) = 18.93, p = 0.001). Several ToM tasks characteristics (e.g. modality of stimuli, type of mental state), were significantly related to the magnitude of the associations between ToM and executive functions, visuospatial/problem solving, attention and episodic memory. These results suggest that ToM is linked to a wide range of neurocognitive abilities in schizophrenia, and that ToM tasks are a significant moderator of these associations. The assessment and treatment of ToM should consider the neurocognitive profile of each patient to understand his difficulties and to tailor interventions.