From cradle to Tic: early developmental profiles of tourette syndrome and its comorbidities in the MoBa cohort.

Tourette syndrome (TS) is heterogeneous and frequently co-occurs with attention-deficit/hyperactivity disorder (ADHD) and other recorded neurodevelopmental diagnoses. We examined whether early parent-report questionnaire profiles in the Norwegian Mother, Father and Child Cohort Study (MoBa) differed across later TS diagnostic subgroups, focusing on developmental phenotyping rather than individual-level prediction. The analytic sample included 92,875 children with linked registry follow-up and at least one retained questionnaire predictor at 6, 18, or 36 months. For this project, registry access was limited to ICD-10 F70-F99 diagnoses; the reference group therefore comprised children with no recorded F70-F99 diagnosis in the available project extract, not children known to be free of all psychiatric or somatic diagnoses. Age-specific principal component analysis (PCA), item response theory (IRT), and raw-item profiles were used to describe early questionnaire dimensions relative to the no-recorded-F70-F99 reference group. Twenty-one PCA domains were retained. Differences were small at 6 months and most interpretable at 36 months. TS with ADHD showed the clearest preschool regulation, attention, and externalizing profile, whereas TS with other recorded F70-F99 diagnoses showed broader language, motor, social-communication, sociability/activity, and developmental-concern elevations. TS without other recorded F70-F99 diagnoses showed smaller, more focal elevations. Secondary separability checks were modest, supporting group-level profile differences rather than screening-level prediction.