Intersecting Trajectories: Childhood ADHD, Socioeconomic Deprivation, and Distinct Multimorbidity Patterns in Females

The long-term consequences of ADHD in females remain under-recognised both in research and clinical practice. Multimorbidity (≥2 long-term conditions) is increasingly viewed as a key outcome, yet its prevalence, complexity, and sociodemographic determinants are understudied in this group. In this longitudinal cohort study, we examined the combined influence of childhood socioeconomic deprivation and ADHD on multimorbidity risk in females and used latent class analysis to explore clustering patterns. Three findings emerged: females with childhood ADHD had significantly higher risk of adult multimorbidity; childhood ADHD and socioeconomic deprivation both increased this risk in isolation and synergistically, with 39% of the multimorbidity burden attributable to their interaction; and distinct multimorbidity clusters emerged, with the most adverse marked by psychiatric complexity. These results highlight girls with ADHD from disadvantaged backgrounds as a high-risk group requiring earlier, integrated care.