Despite a tenfold increase in ADHD prescriptions, too many New Zealanders are still going without

The number of people accessing medication for attention-deficit hyperactivity disorder (ADHD) in Aotearoa New Zealand increased significantly between 2006 and 2022. But the disorder is still under-diagnosed and under-treated compared to global ADHD prevalence estimates.

ADHD is a neurodevelopmental disorder affecting the part of the brain that helps people plan, control impulses and execute tasks. It is treated primarily with methylphenidate.

Our new research using demographic and dispensing data from pharmacists – showed a tenfold increase in dispensing of ADHD medication for adults over the study period. During the same time frame, there was a threefold increase in prescriptions for children.

Despite this, there remain serious access and equity issues. New Zealand will need to look at why some people are not getting help, and consider whether the treatment options are fit for purpose.

The rise of ADHD diagnoses

We speculate there are multiple reasons for the rise in ADHD diagnoses and treatment over the past two decades.

In New Zealand and elsewhere, people are becoming more literate about mental health issues, including disorders such as ADHD, depression, anxiety and autism. With increasing literacy, comes greater demand for treatment.

People may be becoming less tolerant of symptoms affecting their day-to-day activities. Generally accepted symptoms of ADHD in adults include impulsiveness, disorganisation and problems prioritising focusing on tasks and poor time management.

Read more: More adults are being diagnosed as neurodivergent. Here's how employers can help in the workplace

While everyone may have some symptoms similar to ADHD at some point in their lives, ADHD is diagnosed only when symptoms are severe enough to cause ongoing problems. These persistent and disruptive symptoms can be traced back to early childhood.

The vast majority of medications prescribed in New Zealand are stimulant medicines. There is an assumption these medications will agitate and increase activity in whoever takes them.

But for many people with ADHD, the medication allows attention to be better focused. In fact, people become less agitated and more able to function within the demands society places on them.

The treatment gap in New Zealand

While there has been a significant increase in prescriptions for adults with ADHD since 2006, our data suggest it is likely there is a large number of people with ADHD who are not receiving treatment.

In 2022, 0.6% of the adult population in New Zealand was receiving treatment for ADHD. This compares to an estimated 2.6% of adults with the condition. This suggests a large treatment gap exists.

There were noteworthy gender and ethnicity differences across the age span within the data. Three quarters of children dispensed ADHD medication were male, whereas the gender split was more even for adults.

There is debate about the differences in ADHD symptoms between the genders. Some have suggested males tend to exhibit more external symptoms of ADHD, including hyperactivity. They are, therefore, more likely to be diagnosed as children. It is believed females are relatively under-recognised because they exhibit less obvious symptoms such as anxiety.

Dispensing of ADHD medication for Māori for all ages was in line with population demographics. However, adult Māori only made up 10% of people receiving prescriptions for ADHD medication, despite making up 17% of the population.

The barriers to diagnosis and treatment

Receiving treatment for ADHD relies on access to a range of assessment and treatment options. Also, the prescription of methylphenidate requires special authority from Pharmac (the government body overseeing funding and supply of medications) and endorsement by a paediatrician or psychiatrist.

In Aotearoa New Zealand, access to public mental health services is heavily restricted due to a workforce facing considerable strain. Some district health boards do not assess adult ADHD at all.

Read more: ADHD in adults is challenging but highly treatable – a clinical psychologist explains

This means many ADHD assessments are now undertaken in the private sector at a cost of between NZ$1,000 and $3,000. The price of diagnosis and treatment is creating access and equity issues for those unable to afford the expensive assessments.

It is possible that, with greater access to ADHD assessments and treatment, the negative individual and societal effects would reduce. The known burdens associated with ADHD include lower productivity, health and education system costs, and reduced quality of life.

Increasing access to ADHD assessments and treatment will require more professionals with the skills to complete ADHD assessments, as well as revisiting the current prescribing restrictions and PHARMAC authorisation system.

This won’t be straightforward – but it needs to be a priority if New Zealand is to address the gap between those who have ADHD and those who are able to receive diagnoses and treatment.