Attention-deficit/hyperactivity disorder in neurofibromatosis type 1

Aim: To characterize age-specific patterns of attention-deficit/hyperactivity disorder (ADHD) symptoms and identify symptom profiles, as well as their associations with demographic and disease-specific factors, in a large international sample of children with neurofibromatosis type 1 (NF1). Method: Observational data from 904 assessments in 656 children with NF1 (age mean [SD] 9 years 6 months [3 years 11 months]; range 3–18 years; 43.4% female) across eight institutions were pooled. With a cross-sectional design, age-varying ADHD symptom patterns were examined using time-varying effect modeling; latent profile analysis was used to classify symptom profiles. Results: Across ages 3 to 17 years, children with NF1 showed elevated inattention and hyperactivity/impulsivity relative to the normative mean, with inverted U-shaped age patterns peaking around age 10 years. Four ADHD profiles emerged: typical range (n = 416; 46.0%); severe combined (n = 199; 22.0%); mild combined (n = 181; 20.0%); and predominantly inattentive (n = 108; 12.0%). Greater symptom severity was associated with female sex and lower parental education. Interpretation: ADHD symptoms in children with NF1 were elevated across ages, with the greatest symptom burden in middle childhood, alongside substantial heterogeneity in symptom presentation. These findings underscore the need for early recognition, ongoing monitoring, and individualized interventions to mitigate long-term academic, social, and functional impacts.