People living with mental illness could have a shorter life expectancy by 20 years, new research has found.
It's a disparity that's been described as a "human rights scandal."
Mental Health Foundation chief executive Shaun Robinson told TVNZ1's Breakfast there are "a whole range of reasons" behind how mental health can affect people's life expectancy so drastically.
"Often, people's physical health is not being considered fully when they're getting support for their mental health issues," he said.
"So it can be looking at the pre-existing physical health issues and really kind of segmenting our health services so we're only looking at mental health and we’re not looking enough at physical health.
"Sometimes, people with mental health issues are not really believed when they're talking about their physical health. It's kind of seen as just part of their mental health situation, so things like cancers can go overlooked for far too long."
Mr Robinson said much of the concerns over health issues being ignored can be attributed to the side-effects of some of the medications being prescribed to mental health patients.
"They can have real impacts on weight gain and other issues like that, which obviously have impacts on heart disease, obesity, those kinds of issues, and we're not really addressing the whole person and thinking about the kind of lifestyle issues that can also be addressed and encouraged which really are beneficial to all of us.
"Things like exercise, things like smoking cessation, reducing alcohol, diet, sleep – and in fact, all of these can be part of addressing a person's mental health and wellbeing, as well as being very important to their physical wellbeing."
He said it's taken a long time for the medical community to make the link between physical and mental health due to "the whole clinical approach to mental health and the way the medical profession is trained."
"It's very 'this is what we're looking at and we don't look outside this box.' I think it is changing – things like mindfulness, things like spending time in nature, actually prescribing people take exercise and having encouragement to do that – that is becoming more common, but it's certainly not common enough."
Mr Robinson said people with previously diagnosed mental health issues can be discriminated against when seeking help for their physical health issues by people working in the health system.
"It is a form of discrimination and people experiencing mental health issues are discriminated against in a myriad of ways, and it definitely does come through in the health system," he said.
"These are well-meaning people, well-meaning doctors and nurses, but again, part of their training – and especially in New Zealand, when the services are under extreme pressure, of course it's much harder to think holistically to actually kind of share the care with physical health professionals as well so we’re not in an ideal situation to actually solve this, but I think the efforts are there to try and address this because it is a human rights issue, it is an issue of discrimination."
He said: "I myself live with bipolar. Now, I intend to live just as long as anybody else in the population and I deserve the support. So does everybody else with mental health issues in order to live my full life."