Mental health multimorbidity and physical conditions in children aged 6-17 years in the United States.

BACKGROUND: The rising prevalence and early onset of mental health problems among children and adolescents pose a critical public health challenge. AIMS: This study aimed to identify distinct profiles of mental health multimorbidity, examine their associations with physical conditions and evaluate the dose-response relationships between the number of mental health multimorbidities and physical condition risk. METHODS: Using cross-sectional data from 30 556 children aged 6-17 years in the 2023 United States National Survey of Children's Health, we applied latent class analysis to derive multimorbidity profiles from nine mental health problems. Multivariable logistic regression assessed associations with 15 physical conditions. Dose-response relationships were evaluated based on the number of co-occurring mental health conditions. RESULTS: Four distinct profiles were identified: developmental delay/intellectual disability with mixed problems (DD/ID with MP, 8.0%), emotional problems (8.2%), attention-deficit/hyperactivity disorder with behavioural problems (ADHD-BP, 8.0%) and low mental health concerns (75.8%). The three clinical profiles exhibited a significant physical disease burden. DD/ID with MP showed the strongest associations with neurological and hearing conditions. Although emotional problems and ADHD-BP shared a similar risk profile, emotional problems showed stronger associations with headaches and respiratory issues. A dose-response relationship was observed, with physical disease risk increasing for each additional mental health problem, particularly among children with > 3 disorders. CONCLUSIONS: Mental health multimorbidity is significantly associated with increased physical condition risk in a profile-specific and dose-dependent manner. This underscores the need for integrated clinical strategies that account for transdiagnostic patterns and comorbidity burden to enhance risk stratification and tailor interventions in paediatric populations.