Lately, I feel that many studies have confirmed what older studies have already shown. On the other hand, confirmation and extra nuance are always welcome. And, of course, a review study tries to summarize what other studies have found.  This review study is another example as it has found that teachers may be attributing signs of age-related immaturity in children to conditions such as Attention-Deficit/Hyperactivity Disorder (ADHD) or Autism Spectrum Disorder (ASD).

From the press release:

The results of the study, which are published in the journal European Child and Adolescent Psychiatry, showed that the youngest students in a class, with birth dates just before the school entry cut-off date, were overrepresented among children receiving an ADHD diagnosis or medication for the condition.

Experts looked at how being one of the youngest children in a class can influence the likelihood of being diagnosed with ADHD or ASD. ADHD is a condition where individuals have significant challenges with attention and can be overly active. ASD is a complex developmental condition that relates to how a person communicates and interacts.

Professor Kapil Sayal from the School of Medicine at the University, and senior author of the paper, said: “This review shows that adults involved in identifying or raising concerns over a child’s behaviour — such as parents and teachers — may be inadvertently misattributing relative immaturity as symptoms of ADHD. The child’s age in relation to their classmates (their ‘relative’ age) needs to considered when making this kind of diagnosis.”

Detailed searches were used to identify all studies written on this topic worldwide. Researchers reviewed the 32 studies identified. Most of these studies focused on ADHD and two focused on ASD.

The findings confirmed that younger students in the school year are more likely to be diagnosed with ADHD and receive medication for this, compared to their older classmates. The scale of this ‘relative age’ effect varied between the studies.

For ASD, the youngest children in a class were also more likely to be diagnosed but more research is needed due to there only being a small number of studies available.

Interestingly, there was a more notable difference in how teachers rated these younger children compared to how parents do.

Dr Eleni Frisira, from the School of Medicine and lead author of the study, said: “Teachers play an important role in identifying ADHD symptoms in children. Our findings suggest that they can be more likely to rate younger students in a class as having ADHD symptoms than their older classmates. It is important teachers are supported in considering the relative age of a child in a classroom when ADHD is being queried.”

Dr Josephine Holland, one of the authors of the paper added: “This phenomenon has been shown in research for over a decade, but knowing about it does not seem to be changing practice.”

The research emphasises how important it is to consider a child’s age in relation to their classmates when assessing for and diagnosing conditions like ADHD and ASD. This is an important take-home message for healthcare professionals who assess young children, but also for teachers and parents, when observing and reporting symptoms.

Abstract of the study:

Youngest students in their class, with birthdates just before the school entry cut-off date, are overrepresented among children receiving an Attention-Deficit/Hyperactivity Disorder (ADHD) diagnosis or medication for this. This is known as the relative age effect. This systematic review and meta-analysis summarises the evidence on the influence of relative age on ADHD symptoms, diagnosis and medication prescribing. As no review to date has investigated the association with autism spectrum disorder (ASD) diagnosis, this is also examined. Following prospective registration with PROSPERO, we conducted a systematic review according to the PRISMA guidelines. We searched seven databases: Medline, Embase, PsycInfo, Web of Science Core Collection, ERIC, Psychology and Behavioural Sciences Collection, and Cochrane Library. Additional references were identified from manual search of retrieved reviews. We performed a meta-analysis of quantitative data. Thirty-two studies were included, thirty-one investigated ADHD and two ASD. Younger relative age was associated with ADHD diagnosis and medication, with relative risks of 1.38 (1.36–1.52 95% CI) and 1.28 (1.21–1.36 95% CI) respectively. However, risk estimates exhibited high heterogeneity. A relative age effect was observed for teacher ratings of ADHD symptoms but not for parent ratings. With regard to ASD, the youngest children in their school year were more likely to be diagnosed with ASD. This review confirms a relative age effect for ADHD diagnosis and prescribed ADHD medication and suggests that differences in teacher and parent ratings might contribute to this. Further research is needed on the possible association with ASD.