People with untreated ADHD are having their lives cut short by an average of 13 years, yet the worst affected are the least able to get treatment, psychiatrists say.
However, many in the profession are worried about allowing GPs to diagnose Attention Deficit Hyperactivity Disorder, fearing there is a risk other complex conditions could be missed - or drugs could end up in the wrong hands.
Stan*, who is in his 30s, believes he would not be alive today without his ADHD diagnosis two years ago.
"Prior to being diagnosed, my life was an absolute train wreck - the number of car accidents I've been in is ridiculous, the number of drink driving convictions, even before being able to legally purchase alcohol.
"I had two very serious suicide attempts, which ended me up in the [psychiatric] ward."
For the best part of a decade, he tried to get help, being treated at various times for depression, anxiety, bipolar disorder and substance abuse.
He struggled with work and relationships.
"I just couldn't pass through things emotionally. I got stuck, couldn't sleep, had no impulse control or executive function. Just trying to work through simple tasks would get me down."
After three or four sessions with psychiatrist Marie Bismark, they decided to trial ADHD medication, which has had a life-changing impact.
"It allows me to hold one thought - I certainly couldn't have done that before."
Bismark no longer works in the public system, because of the unsustainable workload.
ADHD Treatment aceess easier for the rich
In an interview with Morning Report, she said many publicly-funded community mental health clinics were no longer assessing or treating adult ADHD.
"Given how severe the impairments can be and how much ADHD can affect people's functioning, that feels like a public community mental health clinic opting out of treating bipolar disorder.
"If people have moderate to severe impairment, they should be able to access treatment no matter what the cause."
People with untreated ADHD had 13 years' reduced life expectancy, due to higher rates of unintentional injuries, road accidents, substance abuse, suicidality and imprisonment, she said.
"At least a quarter of people in prison have ADHD, but their risk of reoffending goes down a third if you treat them."
Should GPs be allowed to diagnose and treat ADHD?
A private assessment for ADHD usually costs more than $1000, and adult patients must have their Special Authority for medication renewed by a specialist every two years.
That is set to change, with Pharmac currently consulting on plans to let GPs renew prescriptions once a diagnosis has been made.
If approved that could take effect from 1 December.
Some GPs and advocates want the government to go further and allow family doctors with specialist training to be allowed to diagnose the condition.
However, at a session on ADHD at the Royal Australian and New Zealand College of Psychiatrists conference in Wellington on Wednesday, several specialists warned against removing too many safeguards.
The head of the Anxiety Disorders Service in Christchurch, Dr Ben Beaglehole, said the data showed some groups (including adult Māori) were under-treated, and it was unfair that cost was a barrier.
Mental health services in Christchurch were no longer accepting referrals for adult ADHD assessments.
However, Dr Beaglehole said he had "misgivings" about the push to let GPs make diagnoses.
"I find it a very difficult diagnosis to make in the context of complex co-morbidity.
"I find it particularly difficult these days because so many people know what an ADHD assessment look like, they know all the criteria - it's quite different to screening someone for schizophrenia."
Research led by Beaglehole showed there was a ten-fold increase in stimulant prescriptions for adults between 2006 and 2022, and a three-fold increase for children.
Treatment rates peaked in 2022, at 1.72 percent of the child population (under 18 years) and 0.56 for adults, which is still lower than the estimated prevalence of 5-7 percent.
Risk stimulant medication could be "abused"
An addiction specialist warned the sudden increase in stimulant use could be doing more harm than good.
Dr Sam McBride, clinical lead of addiction services in Capital Coast Health, likened the surge in prescribing to the deadly opioid epidemic which killed over a million people in the United States.
ADHD was also the subject of aggressive marketing, political lobbying by drug companies, which also minimised the potential harms - including the risk of psychosis and cardiovascular problems.
There were specialist clinics popping up with a narrow focus on ADHD, and doctors with a financial interest framing "the problem" as a human rights issue.
"Industry is doing what industry does. Notably, ADHD is an industry's dream: you've got a life-long disorder, you've medication as the first-line intervention regardless of severity and it covers the whole lifespan."
Dr McBride said there were more patients seeking a specific diagnosis of ADHD, based on self-diagnosis via TikTok or other social media.
"More broadly, ADHD in the community can be seen as providing sense of identity, an explanation for one's life, identities have coalesced around diagnosis, often pathologising what might be considered normal behaviour and this dynamic is being reinforced by social media algorithms."
When he filled out online screening and confessed to "avoiding tasks requiring sustained mental effort", he was urged to seek a specialist opinion.
"That's not to deny that ADHD doesn't exist, that's not to deny that people benefit from treatment.
"But it does require us to be sceptical and to consider how changes to practices have occurred."
He likened himself to "the sanitary worker of the psychiatric service - cleaning up the mess that my colleagues leave behind".
"I'm surprised at the number of people I see who are prescribed stimulants in the context of an active eating disorder, anxiety disorder, addiction - and this is often by people who claim expertise in ADHD.
"There's little sense of how those things are matched together or whether one is worse than the other. So we can expand out to GPs, but we're probably going to make the paradigm worse."
However, fellow psychiatrist Rosie Edwards, who treats ADHD in public and private practice, disagreed the profession was "doing it badly".
"There is strong evidence that depending on the type of eating disorder, concurrent treatment with stimulant medication can be helpful. And the same with anxiety. Sometimes people have been calling something anxiety that's not actually anxiety."
*Name changed to protect privacy