New research critically examines the timing of when a child is diagnosed with attention-deficit hyperactivity disorder (ADHD), suggesting that immaturity may influence behavioral characteristics that are erroneously attributed to ADHD.
ADHD is typically diagnosed in childhood and manifests as an inability to sustain attention and control activity levels and impulse control. Some reports have indicated a prevalence of up to 15 percent in Western countries.
Although the causes of ADHD are still unknown, a new study scheduled for publication in The Journal of Pediatrics found that a child’s age at school entry may have an effect on the diagnosis of ADHD. That is immaturity may result in characteristics/behaviors labeled as ADHD.
Dr. Mu-Hong Chen and colleagues from Taipei and Taoyuan, Taiwan, examined cohort data from 378,881 children ages four to 17 years from 1997 to 2011. From this data set the researchers evaluated the prevalence of being given a diagnosis of ADHD and/or prescribed ADHD medication.
Using the Taiwanese and traditional American annual cut-off birthdate of August 31 for school enrollment, the researchers compared the youngest children in a grade (those born in August) with the oldest (those born in September). They then assessed whether age was associated with being diagnosed with ADHD and/or being medicated.
When looking at the database as a whole, children born in August were more likely to be diagnosed with ADHD and/or receive ADHD medication than those born in September. When broken down and analyzed according to age, only preschool or elementary school-aged children born in August had an increased risk of being diagnosed with ADHD and receiving ADHD medication.
This characterization only applied to children however, as adolescents born in August did not have an increased risk of ADHD diagnosis. Researchers believe this finding may imply that increasing age and maturity lessens the impact of birth month on ADHD diagnoses.
Worldwide, the number of children and adolescents being diagnosed with ADHD or receiving a prescription for ADHD has significantly increased. Evidence shows that relative age, which may be a proxy of neurocognitive ability, may increase the likelihood of ADHD diagnosis and medication.
According to Dr. Chen, “Our findings emphasize the importance of considering the age of a child within a grade when diagnosing ADHD and prescribing medication to treat ADHD.”