Sensory hyper- and hyporeactivity at age 3 as transdiagnostic prospective markers of neurodevelopmental, emotional, and behavioral difficulties at age 8: A population-based cohort study in the Norwegian Mother, Father, and Child Cohort Study (MoBa)

Abstract Atypical sensory reactivity is a core feature of autism but has mostly been studied in small, clinical, cross-sectional samples. We examined whether early sensory atypicalities are transdiagnostic or unique to autism and whether sensory modality and persistence matter. This study is based on the Norwegian Mother, Father, and Child Cohort Study (MoBa), a Norwegian population-based cohort in which race/ethnicity is not recorded. In a subsample ( N = 113,785; 51.0% boys, 49.0% girls; child age at the age-8 assessment M = 97.6 months, SD = 2.0; analytic samples n ≈ 31,000–33,000), three parent-reported markers at age 3 (auditory hypersensitivity, reduced pain sensitivity, and unusual sensory interest) predicted seven age-8 outcomes: autism traits, ADHD inattention and hyperactivity, oppositional and conduct problems, anxiety, and depressed mood. In robust regressions and a three-wave persistence analysis, sensory atypicality predicted all domains (standardized β). Autism traits were most strongly predicted ( β = 0.18 composite; 0.42 persistent), yet not uniquely (autism–ADHD difference = 0.05 SD). Auditory hypersensitivity was related to internalizing problems, reduced pain sensitivity to externalizing problems, and lower anxiety. Cumulative load showed a graded dose–response. Effects were small, indicating population-level rather than individual predictive value.