Clinicians should be cautious when assessing test results of children with autism who are evaluated for attention-deficit/hyperactivity symptoms because screening tools do not appropriately distinguish those symptoms with symptoms associated with autism spectrum disorder, according to recently published study findings.
“It is estimated that as many as half of children with [autism spectrum disorder (ASD)] also have an ADHD diagnosis, and about half of those children don’t respond to stimulant treatments like Ritalin [methylphenidate hydrochloride, Novartis],” Benjamin E. Yerys, PhD, a psychologist in the department of child and adolescent psychiatry and behavioral sciences at The Children’s Hospital of Philadelphia, told Infectious Diseases in Children. “As health care providers, it is our responsibility to provide our patients with clinically appropriate guidance that will help them to manage behaviors associated with autism or ADHD. Some of the social symptoms associated with autism can be mistaken for inattention.”
To determine whether ADHD symptoms are accurately measured with current screening tools in children with autism, including caregiver/teacher ratings from questionnaires, Yerys and colleagues conducted a retrospective examination on the incidence of ADHD in 386 children aged 7 to 17 years with a diagnosis of ASD. The researchers conducted the study using the ADHD rating scale fourth edition (ADHD-RS-IV) and its association between participant behaviors and characteristics and the underlying construct factors inattention, hyperactivity and impulsivity in children across caregiver and teacher ratings as related to community-based and ADHD samples. In addition, the researchers examined whether hyperactivity and impulsive behaviors decreased with age in children with ASD.
The retrospective analysis showed that the ADHD-IV-RS delivered unsatisfactory confirmed factor data for the inattention variables and hyperactivity/impulsivity in children with ASD, despite general scale correspondence with an expected two-factor solution. Caregiver ratings showed 39% of study children had scores above clinical cut-offs in symptoms for inattention and 27% for hyperactive and impulsive symptoms; however, teacher ratings showed only 24% for inattention symptoms above clinical cut-offs and 13% for hyperactive and impulsive symptoms. Further, the three-factor solution for caregiver ratings identified several problems for children with ASD on the ADHD-IV-RS. Caregiver and teacher ratings were moderately associated within and across ADHD symptom domains (r = 0.25-0.43). Small correlations were observed within the internalizing problems domain (r < 0.18) in caregiver and teacher ratings compared with ADHD-IV-RS, and hyperactive and impulsive symptoms decreased with child age in both caregiver (r = –0.31) and teacher (r = –0.28) ratings.
ADHD rating scales may not be catching the nuances correlated with ASD, the researchers wrote.
“I think the most important thing primary care physicians can do with this information is to exercise greater caution in interpreting ADHD screeners if the child has a diagnosis of autism or if the parent (or physician) suspect the child has autism,” Yerys told Infectious Diseases in Children. “For these cases, it will be helpful to get consultation from a developmental or behavioral specialist.” – by Kate Sherrer
Disclosure: The researchers report no relevant financial disclosures.