Canberra, February 10 (The Conversation) – A new study shows that the number of Australian children prescribed medication for attention-deficit hyperactivity disorder (ADHD) has increased tenfold in 20 years, but this trend is not linked to socioeconomic status.
Previously, children in the lowest socioeconomic areas were most likely to be prescribed ADHD medication. However, this has reversed, with children from wealthier families now being most likely to be prescribed medication.
So, does this mean that the availability of ADHD medication depends on how much your parents earn?
Not necessarily. Overall, the variation in prescription levels has narrowed over the past 20 years. However, there is still a significant difference between the wealthiest and poorest areas.
What is ADHD?
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ADHD is the most common diagnosis for children in Australia. While symptoms vary, it is associated with hyperactivity and/or inattention, which can cause difficulties at home, school, or work.
The most common treatment for ADHD is psychostimulant medication.
What we studied
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Our research team reviewed two decades of national data from 2003 to 2022. We looked at prescription records from Australia’s Pharmaceutical Benefits Scheme (PBS), which subsidizes medication.
We wanted to understand how prescription rates change and differ across states and territories. We also wanted to know whether living in a wealthy or disadvantaged area affects access to medication.
To compare areas based on ADHD prescriptions, we used a standardized ratio. If an area had the national average rate of prescriptions, its score was 1.0. Higher than one means more prescriptions than average, while lower means fewer.
What we found
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Between 2003 and 2022, the number of children aged 5–17 on ADHD medication increased from 20,147 people (0.5% of the youth population) to 246,021 young people (4.2%).
The biggest increase occurred in 2020 and 2021 during the COVID pandemic, when prescriptions for older teens (15–17 years) increased by 2.1 percentage points, from 3.1% to 5.2%.
Lockdowns may have led to increased awareness and a greater focus on neurodiversity and learning issues.
In the 1990s, access to ADHD medication was largely dependent on where you lived or your parents' income.
Some states, such as Queensland and Western Australia, prescribed more medication than others. Our data shows that rates were even higher in Western Australia and Tasmania in 2003.
When we adjusted for population size, we could see how these trends varied across states and territories over the 20 years.
Over time, the differences have narrowed.
This suggests that clinicians are becoming more consistent in their diagnosis and treatment of ADHD. This is largely due to efforts to standardize best practices across the nation and reduce the variations that existed 20 years ago.
As more states and territories expand access to GPs, robust training and standardization will be vital to avoid past inconsistencies.
So, how does wealth come into it?
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For a long time, the children in the most disadvantaged areas were more likely to be prescribed ADHD medication.
This may be because behavioral symptoms can be more noticeable when families and schools have fewer resources to manage them.
However, this trend has reversed. Nowadays, children from wealthier families are most likely to be prescribed medication.
In 2003, richer areas had the lowest rates of ADHD medication use, with a ratio of 0.612. By 2021, this had increased to 1.245.
At the time, seven out of ten areas had ratios between 0.948 and 1.039, while the lowest 10% had a ratio of 0.708.
Why the switch?
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This is likely due to increased demand and the health system's ability to meet it.
Now, getting a diagnosis can take multiple appointments, psychological assessments, and months on a waiting list. Poorer families may face longer waits or may not pursue diagnosis and medication if it seems unaffordable.
However, this data shows that, on average, most areas now have rates close to the national average. So, the biggest changes have occurred in the wealthiest and poorest income groups.
Limitations of the data
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It’s important to note a few limitations. The data only includes prescriptions filled through the PBS system. This means prescriptions from private medical systems are not included, which may explain why the highest postcodes have even higher rates.
The study also couldn't look at the influence of culture or ethnicity, since the data was anonymous.
And while stimulants are mainly prescribed for ADHD, a tiny number are also used to treat other conditions (such as narcolepsy).
Diagnostic guidelines have shifted over the years, most notably when guidelines changed to allow diagnosis of ADHD and autism in 2013, but this did not result in a notable jump in prescriptions in our study.
The real growth came steadily over time, then sped up around COVID since 2020.
Importantly, the study didn’t look at how many repeat prescriptions were taken each year or compare individual postcodes to the national rate, so it does not speak to whether ADHD is being overdiagnosed or overmedicated in some postcodes.
What does it all mean?
Our findings show that more people are accepting ADHD and seeking help. This points to better acceptance of neurodiversity, more consistent care, and a society trying to support all its children.
More standardized practices and consistent care means we’re moving away from the "postcode lottery" effect, where treatment depends too heavily on where you live.
However, the flip in highest diagnosis ratios from the poorest postcodes to the richest means we still need to look closely at access and equity of treatment. (The Conversation) AMS