Your child’s risk of ADHD or autism diagnosis depends on their age compared to classmates, scientists say

BEING one of the youngest children in the class means your child could be more likely to receive an ADHD or autism diagnosis, scientists say.

Younger children with birthdays just before the school entry cut off date are more likely to be diagnosed with the conditions than their older peers, University of Nottingham researchers found.

GettyBeing the youngest in the class could make kids more likely to be diagnosed with ADHD[/caption]

Ratings from teachers and parents will often form an important part of attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD) assessments, researchers said.

Interviews with friends, family, and teachers of a suspected patient are usually conducted to gauge the severity of symptoms.

The fact that more young students receive an ADHD diagnosis or medication for the condition could mean that teachers are mistaking signs of age-related immaturity for the behavioural condition, they claimed.

People with ADHD may have trouble concentrating, appear restless and act on impulse.

Meanwhile, ASD is an umbrella term for a broad range of neurodevelopmental conditions that affect the way people interact and communicate with others.

Senior author Professor Kapil Sayal, from the School of Medicine at the University of Nottingham, 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.”

THE ‘RELATIVE AGE’ EFFECT

Researchers conducted an extensive database search to identify studies written on the topic – they narrowed the pool down to 32 studies to review.

Most of these studies focused on ADHD, while two were about ASD diagnoses.

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.

According to researchers’ analysis, the youngest in the class were 38 per cent more likely to receive an ADHD diagnosis and 28 per cent more likely to be prescribed ADHD medications.

The scale of this ‘relative age’ effect varied between the studies.

“Overall, our results show that teacher ratings for ADHD-related symptoms are more influenced by relative age, in contrast to parent ratings,” the study authors said.

This difference between parent and teacher reporting of ADHD symptoms could be influenced by several factors, researchers noted.

“The higher demands and limited flexibility of the school environment, the presence of large numbers of peers to compare the child with, and the less close and shorter duration of the relationship of teacher to child compared with parent to child could all cause this observational bias in teacher ratings.

“Parents may also be subject to social desirability bias towards their child, potentially overlooking certain behaviours.

“Teacher perceptions and susceptibility to relative age bias may impact a child’s referral and diagnostic process.

“Teachers are more likely to identify ADHD symptoms in younger children in the school year and give higher scores on symptom scales, which are then taken into account by clinicians when doing a diagnostic assessment.”

Study authors also noted that the opposite might also happen, where teachers miss ADHD symptoms in older children due to comparing them to their younger and less mature classmates.

The ‘relative age’ effect on ADHD diagnosis and treatment was more pronounced in in younger children attending primary school and gradually lessened as children reached adolescence.

“This observation suggests that actual age and developmental expectations significantly influence ADHD identification,” the study authors noted.

For ASD, both studies on the subject found that the youngest children in a class were also more likely to be diagnosed with the condition compared to their older peers.

Researchers said: “The reasons behind this are not clear, but it is possible that immature speech or social skills of relatively younger children may be interpreted as traits of autism by referrers.”

But they stressed that more research is needed on the ‘relative age’ effect for ASD diagnoses, as there is only a small number of studies available.

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

The study team said their research emphasises how important it is to consider a child’s age in relation to their classmates when assessing 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, they added.

“Teacher ratings form an important part of ADHD assessments, and so it is important to understand the effect of relative age on their perception of what are normative or immature behaviours,” researchers wrote in the study published in the journal European Child and Adolescent Psychiatry.

“It will be useful to incorporate this phenomenon (the ‘relative age’ effect) in the clinical guidelines and training of healthcare professionals specialising in neurodevelopmental disorders, as well as teachers to help them think critically about children’s symptoms during their assessments.”

GROWING AWARENESS

It’s estimated that 2.6 million people in the UK have ADHD, almost 700,000 of them children.

Symptoms tend to be noticed at an early age and may become more noticeable when a child’s circumstances change, such as when they start school.

Most cases are diagnosed when children are under 12 years old, but sometimes it’s diagnosed later in childhood or even in adulthood.

ADHD can be categorised into two main types – inattentiveness and hyperactivity.

While most people show symptoms of both, this isn’t always the case.

In adults, hyperactivity is less common, and symptoms are more subtle, making them tougher to identify, for example.

A recent think tank report warned that increased awareness of the condition has left people in the UK waiting up to two years for an assessment.