Loneliness is associated with mentalizing and emotion recognition abilities in schizophrenia, but only in a cluster of patients with social cognitive deficits

Background Loneliness is a concern for patients with schizophrenia (SCZ). However, the correlates of loneliness in SCZ are unclear; thus, the aim of the study is to investigate neuro- and social cognitive (SC) mechanisms associated with loneliness in SCZ. Methods Data for the study were pooled from two cross-national samples (Poland/USA) and included 147 SCZ and 103 healthy controls (HC) overall. Data from clinical, neurocognitive, and SC assessments were examined as potential predictors of loneliness in HC and SCZ samples pooled across two sites. Furthermore, Latent Class Analysis (LCA) was used to cluster patients based on SC capacity. Next, the relationship between SC and loneliness was explored in each cluster of SCZ. Results SCZ reported higher levels of loneliness than HC. Loneliness was linked to increased negative and affective symptoms in patients. A negative association between loneliness and mentalizing and emotion recognition abilities was found in the patients with social-cognitive impairments, but not in those who performed at normative levels. Conclusions We have elucidated a novel mechanism which may explain previous inconsistent findings regarding the correlates of loneliness in SCZ. As decreased SC capacity may be linked with loneliness only in patients with observable SC impairments, SC heterogeneity in SCZ needs to be recognized while planning psychosocial interventions targeting loneliness in this group.