Diagnosing ADHD too early? Risk factors.

Dr Shelley Hyman

According to the criteria for diagnosing ADHD, a child must present a number of symptoms such as inattention, impulsivity or hyperactivity before the age of 7. However, studies have shown that only 50% of patients present these symptoms before 7 years of age. (Kessler et al., 2005).

This poses the question of whether age of onset should be modified in the diagnostic criteria. Also a number of studies have explored the influence of external factors that may affect ADHD diagnoses such as school context and age differences.

Elder (2010) wrote a review paper looking at how “subjective comparison” of younger and older children in a kindergarten cohort can affect the prevalence of ADHD diagnosis. He found that children in the younger half of a kindergarten cohort were more likely to be diagnosed with ADHD compared to children in the older half.

However this may be due to the younger cohort being “developmentally immature” compared to the older children. This can be a major problem for the younger part of the cohort as their immaturity is being mistaken for ADHD.

Furthermore, Elder found that “teachers’ perceptions of poor behaviour among the young children in a classroom” could be a reason why those younger kindergarten children were more likely to be diagnosed. This can be detrimental to the children’s future performance especially with this poor behaviour image perceived by teachers.

As a result, younger children who are diagnosed incorrectly with ADHD end up getting prescribed stimulants and drugs for treatment. We do not know all the effects it may have on children especially taken at such a young age.

However, Elder (2010) pointed out that ADHD stimulants can actually harm cardiovascular health and slow down growth rates. Even after treatment has stopped, children’s growth rate is dramatically reduced and the effects may be irreversible.

Overall, immaturity due to age and perception of teachers can influence the diagnostic criteria of ADHD. Misdiagnosing children especially of such a young age can damage the child’s future wellbeing because giving them the ADHD stimulants may slow down growth. The long term effects however are still unknown.

Alanna Wong


  • Elder, T. E. (2010). The importance of relative standards in ADHD diagnoses: evidence based on exact birth dates. Journal of Health Economics, 29,641-656.
Dr Shelley Hyman

About Dr Shelley Hyman

Senior Clinical Neuropsychologist. BSc (psychol) Hons, MClinNeuropsych, PhD (Med) MAPS CCN. Founder and director of the centre that was founded in 2006.

Leave a Comment