Diagnostic overshadowing in a population of children with neurological disabilities: A cross sectional descriptive study on acquired ADHD

Aim: Diagnostic overshadowing refers to the underdiagnosis of comorbid conditions in children with known neurological diagnoses. To demonstrate diagnostic overshadowing we determined the prevalence of attention deficit-hyperactivity disorders (ADHD) in a cohort of children with a wide range of neurological disabilities. Method: The study cohort consisted of 685 children (mean age 10.3 years, SD: 3.1; 425 boys and 260 girls) who visited a tertiary outpatient multidisciplinary clinic for neurological learning disabilities. Patients with ADHD were identified by retrospective chart review using DSM-IV criteria. Results: The prevalence of ADHD in this cohort was 38.8% (266 children); of these children only 28.2% (75 children) were diagnosed with ADHD before referral. Interpretation: ADHD is a common problem in children with neurological disabilities and may be underdiagnosed due to overshadowing of somatic, physical or syndromal features of the disability. In our heterogeneous population ADHD was overshadowed in 71.8% of the cases. This finding may have important implications for diagnosis and treatment of mental health needs in children with neurological disabilities.