More kids are being diagnosed with ADHD for borderline (yet challenging) behaviours. Our new research shows why that’s a worry

During my daughter’s challenging first year of school, we discovered how much effort it took her to sit and learn.

She was the youngest in her class, placing her at higher risk of being diagnosed with ADHD (attention deficit hyperactivity disorder).

While she struggled with attention and hyperactivity, her problems were always more frustrating than truly impairing. Still, constant battles over finishing tasks, the amount of time (and nerves) spent on a child that needs that extra bit of attention and the anger or sadness on her face made me wonder if we should try to get some support.

Maybe a diagnosis could be a straightforward fix to the problem?

What’s the problem?

Increasing awareness of ADHD has led to consistent rises in the number of children diagnosed with and treated for it, both internationally and in Australia. This would be good if it meant we were getting better at finding, diagnosing and helping children impaired by inattention or hyperactivity.

However, my newly published study in JAMA Network Open finds these increases in ADHD diagnoses may be largely due to children like my daughter, whose behaviours fall within a normal (but frustrating) range. I conducted this research with colleagues from the University of Sydney and Bond University.

Our study concluded these children are unlikely to benefit from being labelled with ADHD and may, in fact, be harmed by it.

This surge in diagnoses also results in limited resources being stretched thinner among more children, ultimately taking away from those with severe problems who would benefit from more support.

Read more: How do I know if my child is developing normally?

What is ADHD? And why is it so controversial?

ADHD is a “persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development”.

It’s one of the most common childhood disorders, affecting about 5-7% of children. Over the past decades, debate on the appropriateness of diagnoses has grown in line with the rate of diagnosis.

Allen Frances, a prominent American psychiatrist, has been one of the most vocal critics of the trend. He describes it as the medicalisation of “every day experiences that are part of the human condition”.

However, others suggest the increases in diagnosed children are largely due to improved detection in previously undiagnosed children.

Both sides of the debate claim to have proof. But we were surprised to discover no-one had ever summarised the scientific evidence for the key reasons behind increasing diagnosis rates.

So we reviewed the results from over 300 studies on ADHD over the past 40 years to determine which children are being newly diagnosed and if they benefit. Our study design allowed us to summarise a huge variety of studies in a way not done before.

What we did and what we found

We found that since the 1980s, increasing numbers of school-aged children and adolescents around the world have been diagnosed with ADHD and medicated for it.

We know ADHD-related behaviours exist on a spectrum with no or minimal hyperactivity and inattention on one end and severe ADHD on the other.

Many children can get distracted easily, are forgetful, find it difficult to sit still or wait their turn. In most children, these behaviours are mild enough to not interfere with a “normal” life.

However, there is no clear biological cut-off point above which someone just “has” ADHD. Ways of diagnosing ADHD also vary between countries and change over time, with criteria generally becoming less stringent.

Together, this ensures many potentially new cases could be discovered, depending on how low the bar is set.

Read more: Five warning signs of overdiagnosis

In the US, for example, almost half of all children diagnosed with ADHD have mild symptoms, with only around 15% presenting with severe problems. Only about 1% of all children in an Italian study had severe ADHD-related behaviours. And, in general, children today are no more hyperactive or inattentive than 20 years ago.

All this led us to conclude a substantial proportion of these additional diagnoses (children who would not have been diagnosed 20 years ago) are, at best, borderline cases.

For example, one study shows while diagnoses increased more than five-fold over ten years in Sweden, there was no increase in clinical ADHD symptoms over the same time. This means that with the lowering of the diagnostic bar, children diagnosed with ADHD are, on average, less impaired and more similar to those without an ADHD diagnosis.

As a result children like my daughter, who are the youngest in their class, are at risk of being labelled with ADHD because their relative immaturity can be enough to push them over the threshold into the zone of “abnormal” behaviour.

Why it’s important to get it right

For children with mild symptoms

Children with mild ADHD symptoms are unlikely to benefit from a diagnosis. They (and their families) also incur substantial costs as well as potential harms from the diagnosis and treatment. That’s because:

• instead of drumming up extra support, an ADHD label can have negative social, psychological and academic effects, when compared to similar young people without a diagnosis

• medication reduces symptoms to a lesser extent in children with mild ADHD (however it is beneficial in many severe cases)

• medication for young people with milder symptoms also has no positive, but a potential negative, effect on academic outcomes (such as maths and reading scores) when compared to unmedicated young people with similar behaviour. Also, medication doesn’t reduce the risks of injuries, criminal behaviour and social impairment as much as in those with severe symptoms.

Read more: Weekly Dose: Ritalin, helpful for many with ADHD but dangerous if abused by those without it

For children with severe symptoms

It’s also important children with more severe ADHD symptoms are correctly diagnosed so they don’t miss out on much-needed support.

With ever-increasing diagnosis rates of ADHD, schools are increasingly struggling to adequately support every child with a diagnosis: the slice of funding and support every child can receive gets smaller and smaller, the more children are included.

In turn, this often means those with the most severe problems get left behind.

Read more: ADHD prescriptions are going up, but that doesn't mean we're over-medicating

What can we do?

In light of the potential risks associated with diagnosing a child with milder ADHD symptoms, we recommend doctors, parents and teachers work together following a “stepped diagnosis approach”. This ensures swift and efficient diagnosis and treatment in severe cases. For those with milder symptoms, taking some time to watch and wait may mean many of them won’t need to be labelled or treated.

Not only will this avoid potential harm for individual children, it also ensures resources are allocated where they are needed most and will be most effective.

Co-authors on this article were: Alexandra Barratt, Professor of Public Health, University of Sydney; Katy Bell, Associate Professor in Clinical Epidemiology, Sydney School of Public Health, University of Sydney; and Rae Thomas, Associate Professor, Bond University.