ADHD Children Functionally Impaired by Grade 2

Pam Harrison

September 30, 2014

Children with attention-deficit/hyperactivity disorder (ADHD) perform well below their peers who do not have ADHD on multiple functional domains as early as grade 2, a new community-based study shows.

Daryl Efron, MD, Murdoch Children's Research Institute, Melbourne, Australia, and colleagues found that children with ADHD between 6 and 8 years of age were 11.0 times more likely to meet criteria for externalizing disorders than non-ADHD control children (P < .001).

They were also almost 3 times more likely than control individuals to meet criteria for internalizing disorders (P = .02).

On both reading and math computation, "striking" differences in academic performance were again observed between children who had ADHD and control children, equating to nearly a full standard deviation for both literacy and numeracy, the researchers report.

Children with ADHD were also more likely than control children to have problems with their peers according to both parent and teacher reports.

Yet prior to study enrollment, only 17% of children in the ADHD group had been diagnosed with ADHD, and only 13% were taking a medication for it.

"In their second year of school, children who had ADHD performed worse than controls across all functional domains, yet only a minority had been formally diagnosed with ADHD," investigators write.

"Findings highlight the need for earlier diagnosis and intervention."

The study was published online September 29 in Pediatrics.

High Comorbidity Burden

Participants were recruited from 43 elementary schools in metropolitan Melbourne, Australia.

The Conners 3 ADHD Index was distributed to parents of all second grade children in participating schools. Teachers completed the same measure.

Children were defined as screening negative for ADHD if their score on the ADHD Index was less than the 75th percentile (boys) or less than the 80th percentile (girls) by both parent and teacher reports and there was no parent-reported diagnosis of ADHD.

Each positive screen was randomly matched on sex and school to a negative screen.

ADHD Index cases were confirmed, and the presence of mental health comorbidities was assessed using the National Institute of Mental Health's Diagnostic Interview Schedule for Children, Version IV, conducted face-to-face with parents.

Children were classified as having an internalizing disorder if they met criteria for separation anxiety disorder; social phobia; generalized anxiety disorder; posttraumatic stress disorder; obsessive-compulsive disorder; hypomania; or manic episode.

Children were classified as having an externalizing disorder if they met criteria for oppositional defiant disorder or conduct disorder.

Academic achievement was assessed using the word reading and math computation subtests of the Wide Range Achievement Test 4, and social functioning was assessed by using the 5-item parent- and teacher-reported peer problems scale of the Strengths and Difficulties Questionnaire.

A total of 179 children with ADHD and 212 children without were compared across the various functional domains. Among those with ADHD, 93 had the combined ADHD subtype; 64, the inattentive subtype; and 22, the hyperactive subtype.

The most prevalent comorbid mental health disorder in children with ADHD was oppositional defiant disorder, affecting 54.2% of the group.

Children with ADHD were also significantly more likely than control children to have multiple impairments (P < .001).

The authors note that only 11% of children with ADHD had no functional impairments, compared with 57% of non-ADHD control children.

Children with ADHD "had a high burden of mental health comorbidities, were performing markedly worse academically, and had poorer peer relations," the investigators write.

"Our findings suggest that comorbidities are identifiable by early primary school age if symptoms are inquired about systematically."

"This is important," they add, "as children who have ADHD and comorbidities respond optimally to a combination of medication and behavioral interventions."

Dr. Efron reports no relevant financial relationships.

Pediatrics. Published online September 29, 2014. Abstract


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