Photo: 123RF
It is "virtually impossible" for an adult to get referred for a publicly funded ADHD assessment, the organisation representing GP practices says.
A survey by ADHD New Zealand of its members found only a quarter were getting treatment from a psychiatrist or psychologist. Of those waiting for support, a fifth had given up.
Untreated ADHD caused huge disruption to children's education and adults' careers, mental health and relationships, General Practice NZ chairperson Dr Bryan Betty said.
"There are some estimates that up to 40 percent of our prison population have undiagnosed ADHD," he told Nine To Noon.
"So this is a major, major issue for children and adults who have this condition, and a cost to society."
There was "literally no capacity" to do ADHD assessments of adults in many regions, he said.
The only medical professionals authorised to assess and diagnose ADHD are paediatricians, psychiatrists, neurologists or clinical psychologists.
But clinical psychologists can not prescribe Ritalin or other drugs used to treat ADHD, which are "Special Authority" medicines.
Betty said even those who could pay privately or had insurance faced long waits.
"So to talk about wait times is actually not the correct way of positioning this. There is no capacity so referrals are just sent back to the GP."
Even once people were diagnosed and being treated they could have problems staying on medication, Betty said.
This was because they had to be re-assessed by a psychiatrist every two years and those appointments were hard to get.
"This is a major, major issue for children and adults who have this condition, and a cost to society" - General Practice NZ chair Dr Bryan Betty
General Practice NZ has been advocating for Pharmac, Te Whatu Ora and the Health Ministry to sign off on family doctors to get approval to do these reviews.
"If a patient is stable and responding to treatment, and is being monitored by the GP, there's no reason in the world why the GP with appropriate guidelines can't do those renewals.
"And that's an absolute failure in the system at the moment."
GPs with special training could even do the initial assessments in some cases, Betty said.
ADHD NZ chair Darrin Bull said undiagnosed and untreated ADHD had a devastating impact on people's lives.
"We know from Canadian research, if you don't get help, you're 4.7 times more likely as an adult to attempt suicide and for children from Australia, it's two times higher. It becomes a significant mental health issue.
"We know from our research that 50 percent of our members have depression and mental health issues."
An estimated 4 to 6 percent of the population were thought to have ADHD - which was consistent across all cultures.
New Zealand was lagging Australia, which was diagnosing people at twice the rate, he said.
"It's an own goal for the New Zealand health sector and the result is really, really poor outcomes for the 260,000 to 280,000 New Zealanders we suspect have ADHD."
Even within the medical profession, knowledge of ADHD was sometimes lacking, he said.
"My own son just turned 18, GP said 'You'll be happy he doesn't have ADHD any more because it only affects children'.
"If GPs are trained in ADHD they can help our community more effectively and efficiently and really help their overall health.
"GPs are the key."