Mentalizing difficulties are transdiagnostic and explain links between mental health and neurodevelopmental symptoms and social adjustment in school‐aged children

Background Mental health and neurodevelopmental conditions are a leading cause of disability in school‐aged children and are associated with adverse social outcomes. The aim of the current study was to investigate the extent to which mentalizing (also called ‘theory of mind’), the ability to reason about others' mental states is associated with specific mental health and neurodevelopmental symptoms or with a general vulnerability to psychopathology (the ‘P‐ Factor’) and whether mentalizing might explain why children with diverse mental health and neurodevelopmental conditions experience adverse social outcomes. Methods In a pre‐registered study using a transdiagnostic dimensional approach, we collected direct assessments of mentalizing, multi‐informant measures of social adjustment at school, and teachers' ratings of mental health and neurodevelopmental symptoms from a diverse community sample of 1020 8‐ to 13‐year‐old children (54.5% girls). Results High scores on the P‐Factor (a general vulnerability to mental health and neurodevelopmental conditions) were negatively associated with children's mentalizing, = −0.154, 95%CI [−0.219, −0.089]. Once the P‐Factor was considered, there were no unique associations between P‐free symptom factors (i.e., internalizing, externalizing, attention deficit/hyperactivity traits, or autism traits) and mentalizing or social adjustment. Mentalizing partly explained the association between P‐Factor scores and poor social adjustment at school, = −0.072, 95%CI [−0.116, −0.028]. Conclusions The results indicate that theory‐of‐mind difficulties are transdiagnostic and underscore the need for longitudinal work examining whether mentalizing explains links between mental health, neurodiversity and social adjustment.