Is the diagnosis of ADHD influenced by time of entry to school? An examination of clinical, familial, and functional correlates in children at early and late entry points

J Atten Disord. 2014 Apr;18(3):179-85. doi: 10.1177/1087054712445061. Epub 2012 May 24.


Objective: The authors examined the proposed immaturity hypothesis, which suggests that younger children may have developmental immaturity and not ADHD, using data from a large, clinically referred population of individuals with and without ADHD.

Method: The sample consisted of individuals with and without an ADHD diagnosis, ascertained from ongoing studies in our laboratory, born in August (Younger Cohort N = 562) and born in September (Older Cohort N = 529). The authors compared studywide diagnosis rates of ADHD, ADHD familiality patterns, ADHD symptoms, psychiatric comorbidity, and functional impairments between the two cohorts.

Results: Studywide rates of ADHD diagnosis, ADHD-associated symptoms, ADHD-associated impairments, ADHD-associated comorbid disorders, and familiality were similar in the two age cohorts.

Conclusion: Results showed that ADHD-associated familial, clinical, and functional correlates are similar irrespective of age at entry to school, indicating that when ADHD symptoms are present, a diagnosis of ADHD should be considered rather than attributing these symptoms to developmental immaturity.

Keywords: developmental; educational.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Attention Deficit Disorder with Hyperactivity / diagnosis*
  • Attention Deficit Disorder with Hyperactivity / epidemiology
  • Attention Deficit Disorder with Hyperactivity / physiopathology
  • Child
  • Cohort Studies
  • Comorbidity
  • Diagnosis, Differential
  • Family
  • Female
  • Humans
  • Male
  • Schools / statistics & numerical data*
  • Social Class
  • Time Factors