Mental disorders early in life can lead to deadly physical illnesses including cancer, strokes and heart disease, a new study has found.
Researchers from the University of Auckland, the University of Michigan and Duke University in the US examined hospital records of close to 2.3 million New Zealanders, all born between 1928 and 1978.
They analysed 30 years of each person's hospital records.
The study found that people admitted to hospital for a mental disorder had increased risk of dying within the 30-year period, regardless of whether they had also been in hospital for their physical health.
Dunedin psychiatrist Christopher Gale, who stressed he had not read the study but spoke generally about the issue, said he was seeing patients with mental health disorders dying younger than him.
"I'm not talking about people dying by suicide or accidents, though we have far too many of these. These are people with severe mental health issues getting pulmonary disease, dying of heart disease or strokes and they are in their 50s."
"It's really, really tragic for their families."
One of the study's authors, Associate Professor Barry Milne from University of Auckland social research centre COMPASS, said the link could be down to health behaviours of people with mental disorders such as smoking, exercise and diet, or it could be that people with a mental health condition may not be getting as good healthcare as they should.
"Or there's a whole range of specific mechanisms, such as mood disorders leading to stress and inflammation, neurosis might lead to high blood pressure."
Regardless he said it supported the need to screen all patients presenting with mental disorders for symptoms of chronic physical illnesses.
"This suggests the importance of joined-up healthcare services, for example, embedding physical health screening and prevention into mental health treatment."
Milne said he expected to find a link between poor mental health and chronic physical conditions but he was surprised to see how consistent the findings were across all mental health conditions.
"I would have thought psychosis would have had the strongest association but really it was similar across all mental health disorders that we looked at."
Researchers examined presentations of substance use disorder, psychosis, mood disorder, neurotic disorder, self-harm and others.
Chronic physical conditions diagnosed in in-patient hospitals, which affected 20 per cent of the population, included gout, diabetes, chronic obstructive pulmonary disease (COPD), traumatic brain injury, stroke, myocardial infarction, coronary heart disease and cancer.
Milne said these findings also reinforced the need to detect and treat mental health issues early in order to reduce premature deaths.
He stressed these findings were only the tip of the iceberg as data showing mental health presentations to GPs was not available - and that's where people with mental health disorders were more likely to show.
The cohort of 2,349,897 people born in New Zealand between 1928 and 1978 and aged from 10 to 60 at the start of the period.
A further study will investigate the role of mental health in later dementia.
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