Abstract
ObjectiveTo determine whether children with attention deficit hyperactivity disorder (ADHD) and mild intellectual disability (ID) are a clinically distinct ADHD subgroup.Study designThis was a cross-sectional study comparing clinical characteristics (ADHD subtypes, total number of symptoms, and rates of common comorbidities) between children with ADHD and mild ID and those with ADHD and IQ test scores >70, and also between children with ADHD and ID and a general population sample of children with ID alone. The sample comprised a clinical sample of children with ADHD with ID (n = 97) and without ID (n = 874) and a general population sample of children with ID and without ADHD (n = 58).ResultsAfter correcting for multiple statistical tests, no differences were found between the 2 ADHD groups on any measure except the presence of conduct disorder (CD) symptoms and diagnoses. Children with ADHD and ID had higher rates of both (OR, 2.38; 95% CI, 1.71-3.32 and OR, 2.69; 95% CI, 1.69-4.28, respectively). Furthermore, children with ADHD and ID had significantly higher rates of oppositional defiant disorder (OR, 5.54; 95% CI, 2.86-10.75) and CD (OR, 13.66; 95% CI, 3.25-57.42) symptoms and a higher incidence of oppositional defiant disorder diagnoses (OR, 30.99; 95% CI, 6.38-150.39) compared with children with ID without ADHD.ConclusionChildren with ADHD and mild ID appear to be clinically typical of children with ADHD except for more conduct problems. This finding has implications for clinicians treating these children in terms of acknowledging the presence and impact of ADHD symptoms above and beyond ID and dealing with a comorbid CD.
Highlights
Little is known of the clinical presentation and etiology of attention deficit hyperactivity disorder (ADHD) in children with intellectual disability (ID), because those with lower cognitive ability (IQ scores
It has been suggested that ADHD does not occur in children with ID, and that any inappropriate behavior in children with ID is secondary to “mental impairment.”[4]. That view is not supported by current evidence
At the 128-month assessment, 2 of the children in the ID-only group met the criteria for DSM-IV oppositional defiant disorder (ODD) (3.4%), and none met the criteria for DSM-IV conduct disorder (CD)
Summary
Participants were recruited from more than 30 child and adolescent mental health services or community pediatric outpatient clinics in Wales, England, and Scotland for a genetic study of ADHD. Children with a known diagnosis of schizophrenia, autism spectrum disorder (ASD), bipolar disorder, Tourette syndrome, epilepsy, brain damage, or any other neurologic or genetic disorder were excluded. Information on these conditions was derived from a questionnaire completed by the referring clinician, diagnostic interview information obtained from parents, and quality control of genetic data performed as part of the genetic study. A total of 971 children met the inclusion criteria and had sufficient data for analysis All of these children met the DSM-IV11 or Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised (DSM-III-R)[12] criteria for a diagnosis of ADHD, which was confirmed through research diagnostic interviews.[13] The children ranged in age from 5 to 17 years (mean age, 10.1 Æ 2.8 years), and included 148 females (15.2%). Written informed consent was obtained from parents and assent/consent from children
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
