Functional Impairments and Theory of Mind Deficits in Schizophrenia: A Meta-analysis of the Associations.

Schizophrenia is associated with major functioning difficulties. Theory of mind (ToM), the ability to infer the mental states of others, is an important determinant of functioning. However, the contribution of ToM to each specific domain of functioning remains to be better understood. The objectives of this meta-analysis were to document and compare the magnitude of the associations between ToM and (1) different domains of functioning (social functioning, productive activities, and instrumental activities of daily living), each assessed separately for functional performance and functional outcome and (2) different aspects of functioning (functional performance and functional outcome) in schizophrenia. Fifty-nine studies (N = 4369) published between 1980 and May 2019 targeting patients with schizophrenia or schizoaffective disorder aged between 18 and 65 years old were included. Studies were retrieved from seven databases. Correlations were extracted from the articles, transformed into effect sizes Zr and combined as weighted and unweighted means. The strength of the associations between the domains and aspects of functioning were compared using focused tests. A moderate association was observed between ToM and all domains of functioning, with a stronger association between ToM and productive activities compared with social functioning (only for functional outcome [χ2(2) = 6.43, P = 0.040]). Regarding the different aspects of functioning, a stronger association was observed between ToM and functional performance, compared with functional outcome, for overall functioning (χ2(1) = 13.77, P < 0.001) and social functioning (χ2(1) = 18.21, P < 0.001). The results highlight a stronger association of ToM with productive activities and with functional performance, which should be considered in future studies to improve functional recovery in schizophrenia.

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

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.

Determinants of occupational outcome in recent-onset psychosis: The role of cognition.

Working or studying is a common goal among people with recent-onset psychosis. Cognitive deficits have been reported to influence occupational outcome, but to date few studies have evaluated if cognitive deficits independently predict occupational outcome when taking into account other important determinants, such as self-esteem, motivation, length of time absent from employment/school, job/school search behaviours, subjective cognitive complaints and psychotic symptoms. Hence, this longitudinal study aimed to evaluate the role of cognition, as well as other key factors relevant to occupational outcome, to predict occupational status six months after baseline in people with recent-onset psychosis. A total of 27 participants receiving treatment in rehabilitation programs were included in the study. Neuropsychological, psychological, clinical and occupational measures were administered at baseline, and occupational status was collected six months later. Ordinal regression indicated that working memory and length of time absent from employment/school at baseline predicted 48.1% of the variance of occupational status at six months, with both variables showing a unique significant contribution to the model. These results suggest that working memory could be integrated in comprehensive models of occupational outcome in people with recent-onset psychosis. In addition, supported employment and education programs could target cognitive deficits and length of time absent from employment/school to help these individuals to acquire a job or return to school given their strong predictive value on occupational outcome.