Social cognition in multiple sclerosis and its subtypes: A meta-analysis

Background: Multiple sclerosis (MS) is an immune-mediated demyelinating disease that disrupts several social cognitive abilities, including the theory of mind (ToM) and facial emotion recognition (FER). It is unclear how specific ToM subcomponents, including cognitive and affective ToM, are affected in patients with MS and the social cognitive abilities in MS subtypes. Methods: A search of PubMed, Web of Science, and Embase databases was conducted until June 2020. Effect sizes were calculated using Hedges g with a random-effects model. Results: A total of 45 studies were included. Relative to health controls (HCs), patients with MS and its subtypes (including relapsing-remitting MS [RRMS] and progressive MS) exhibited impairments in ToM (g = -0.77, g = -0.70, g = -0.75, respectively), cognitive ToM (g = -0.72, g = -0.83, g = -0.73, respectively), affective ToM (g = -0.84, g = -0.63, g = -0. 50, respectively), and FER (g = -0.62, g = -0.53, g = -1.07, respectively). In addition, there was no difference between progressive primary MS and secondary progressive MS in overall ToM, cognitive ToM, affective ToM, and FER. Compared to patients with RRMS, patients with progressive MS showed no difference in overall ToM, cognitive ToM, and affective ToM but had more serious defects in FER (g = -0.57). Conclusions: These quantitative results indicate that patients with MS and its subtypes have a differential impairment of the core aspects of social cognitive processing (including ToM and FER), which may help develop the structured social cognitive interventions in MS.