Attention-deficit/hyperactivity disorder (ADHD) is a developmental disorder characterised by hyperactivity, inattention and impulsivity, which cause impairments in at least two settings. ADHD is the most common psychiatric disorder affecting children. A recent study published in the September issue of Archives of Pediatrics and Adolescent Medicine aimed to establish the prevalence of ADHD in the US and whether prevalence, recognition, and treatment vary by socioeconomic group. Results were contrary to general public consensus and showed that on a whole ADHD is currently underdiagnosed and undertreated in the community.
A general perception exists that attention-deficit/hyperactivity disorder (ADHD) is overdiagnosed and overtreated, exposing children to potential complications of psychostimulant medications. However, new research conducted in the United States of America has in fact revealed the opposite. A research team headed by Dr. Tanya E. Froehlich, a developmental-behavioural paediatrician at Cincinnati Children’s Medical Centre concluded that only 32% of children who met Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) (DSM-IV) criteria for ADHD were receiving appropriate medication. Thus there is a significant cohort of children with clinically significant inattention and hyperactivity who are not receiving optimal interventions.
This research is the first of its kind using the DSM-IV criteria as the gold standard method for determining the prevalence of ADHD. Prior national population-based studies have primarily used parental report of an ADHD diagnosis, medical record review, or medication use. For the current study, researchers collated data on 3082 children aged 8 to 15 years who participated in the National Health and Nutrition Examination Survey from 2001 to 2004. A strict diagnostic interview schedule instrument was used to assess the presence of ADHD based on DSM-IV criteria. In addition, caregivers conducted telephone interviews regarding health professional attendance and medication use to assess patterns of diagnosis and treatment.
Researchers found that in their nationally representative sample approximately 8.7% of children met DSM-IV criteria for ADHD. This equates to national figures of approximately 2.4 million. Even higher rates are noted in poorer socioeconomic groups particularly for the hyperactive-impulsive subtype. Possible explanations for the heightened rates of ADHD in lower socioeconomic groups include varying rates of in utero tobacco exposure, childhood lead exposure, and complications of pregnancy and delivery. These factors should be focus points for future preventative health strategies.
Despite high levels of public awareness surrounding ADHD, less than half of children fitting criteria had actually been diagnosed by a health professional and less than a third had been appropriately treated. Females were less likely to be diagnosed and poorer children whom have the highest rates of ADHD were the least likely to have received consistent pharmacological interventions.
Under-diagnosis and under-treatment of this disorder has the potential to cause significant impairment in children’s social and educational functioning and impact on the entire family unit. ADHD has been associated with lower rates of school and career achievement and increased rates of substance abuse, incarceration, injuries and car accidents. It is therefore essential that ADHD is identified and managed appropriately to reduce this significant burden.
This study concludes that ADHD is a highly prevalent disorder in the community which is generally being underdiagnosed and undertreated. The high rates and poor treatment patterns in lower socioeconomic groups is of particular concern. Increased research and development is warranted in this field to ensure that all children with ADHD have timely and equitable access to appropriate treatment.
- Froehlich T, Lanphear B, Epstein J, Barbaresi W, Katusic S, Kahn R. Prevalence, Recognition, and Treatment of Attention-Deficit/Hyperactivity Disorder in a National Sample of US Children, Arch Pediatr Adolesc Med. 2007; 161: 857-64.
- Reinberg S. 9% of U.S. Kids Have ADHD – But most aren’t getting the medications they need, researchers say, ScoutNews, LLC, 2007.