Assessing social cognition in patients with schizophrenia and healthy controls using the reading the mind in the eyes test (RMET): a systematic review and meta-regression.

The reading the mind in the eyes test (RMET) - which assesses the theory of mind component of social cognition - is often used to compare social cognition between patients with schizophrenia and healthy controls. There is, however, no systematic review integrating the results of these studies. We identified 198 studies published before July 2020 that administered RMET to patients with schizophrenia or healthy controls from three English-language and two Chinese-language databases. These studies included 41 separate samples of patients with schizophrenia (total n = 1836) and 197 separate samples of healthy controls (total n = 23 675). The pooled RMET score was 19.76 (95% CI 18.91-20.60) in patients and 25.53 (95% CI 25.19-25.87) in controls (z = 12.41, p < 0.001). After excluding small-sample outlier studies, this difference in RMET performance was greater in studies using non-English v. English versions of RMET (Chi [Q] = 8.54, p < 0.001). Meta-regression analyses found a negative association of age with RMET score and a positive association of years of schooling with RMET score in both patients and controls. A secondary meta-analysis using a spline construction of 180 healthy control samples identified a non-monotonic relationship between age and RMET score - RMET scores increased with age before 31 and decreased with age after 31. These results indicate that patients with schizophrenia have substantial deficits in theory of mind compared with healthy controls, supporting the construct validity of RMET as a measure of social cognition. The different results for English versus non-English versions of RMET and the non-monotonic relationship between age and RMET score highlight the importance of the language of administration of RMET and the possibility that the relationship of aging with theory of mind is different from the relationship of aging with other types of cognitive functioning.

Systematic evidence and gap map of research linking food security and nutrition to mental health.

Connections between food security and nutrition (FSN) and mental health have been analytically investigated, but conclusions are difficult to draw given the breadth of literature. Furthermore, there is little guidance for continued research. We searched three databases for analytical studies linking FSN to mental health. Out of 30,896 records, we characterized and mapped 1945 studies onto an interactive Evidence and Gap Map (EGM). In these studies, anthropometry (especially BMI) and diets were most linked to mental health (predominantly depression). There were fewer studies on infant and young child feeding, birth outcomes, and nutrient biomarkers related to anxiety, stress, and mental well-being. Two-thirds of studies hypothesized FSN measures as the exposure influencing mental health outcomes. Most studies were observational, followed by systematic reviews as the next largest category of study. One-third of studies were carried out in low- and middle-income countries. This map visualizes the extent and nature of analytical studies relating FSN to mental health and may be useful in guiding future research.