The UK public vastly underestimate the impact of severe mental illness (SMI) on life expectancy, typically guessing it reduces lifespans by just seven years on average, when the true figure is 15 to 20 years – cutting lives shorter than diabetes, severe obesity and even smoking.
Research by King’s Health Partners, Maudsley Charity and the Policy Institute at King’s College London finds only one in nine (11%) people correctly identify that SMI – which includes schizophrenia, psychosis and bipolar disorder – shortens lives by up to 20 years on average, with this lack of awareness making it a hidden health crisis for the more than 500,000 living with SMI in the UK.
South London and the Maudsley NHS Foundation Trust, along with Guy’s and St Thomas’, King’s College Hospital and King’s College London make up King’s Health Partners.
By comparison, smoking or being severely obese typically reduces life expectancy by 10 years, while type-1 diabetes shortens it by eight.
Based on a nationally representative survey of 2,000 UK adults, the study also reveals limited awareness of why mortality is higher in those with SMI, with half the public wrongly believing suicide is the most common factor, and few recognising the inequalities in which communities and areas are most affected by SMI.
And while there is broad support for improving healthcare for those with SMI, opinions are more mixed on whether this is achievable or a priority for the healthcare system, with younger people particularly sceptical.
More generally, the research finds mental health is now tied with cancer as the biggest perceived health problem facing the UK. And a majority (72%) of the public see mental and physical health as equally important, but they’re less convinced the healthcare system treats them this way (33%) – even if there has been a notable increase since 2019 in the belief that the two have parity.
This shift in perceptions has occurred despite mental health making up less than a tenth of NHS spending, an amount that is expected to fall slightly in 2025/26.
The research comes ahead of a roundtable on 12 November, where leaders from South London and the Maudsley and other King’s Health Partners organisations will bring together NHS, policy and community organisations, as well as people with lived experience, to assess the evidence and find solutions to the stark SMI mortality gap.
Half the public (50%) believe suicide is the most common factor reducing the life expectancy in those with SMI, when it in fact accounts for roughly 9% of excess mortality among this group.
A similarly high proportion – 41% – think drug or alcohol poisonings are a key cause, though in reality preventable physical conditions are the more common factor.
Just 9% of the public correctly recognise cardiovascular disease is a leading driver of reduced life expectancy in those with SMI, while even fewer – 5% – correctly select respiratory problems, despite this group being 6.6 times more likely to die prematurely as a result of such problems.
Professor Matthew Hotopf CBE, Deputy Executive Director at King's Health Partners, said:
People with severe mental illness face one of the greatest health inequalities of our time, dying 15 to 20 years early. Yet our findings show the public has little awareness of the scale of this mortality gap, or that it’s driven primarily by treatable physical health conditions. This hidden health crisis demands urgent attention and King’s Health Partners is committed to driving this change. As a university health partnership between two physical health NHS Foundations Trusts, a mental health NHS Foundation Trust and a world-leading university, we are uniquely placed to test innovations locally while influencing national and global policy and practice to close the mortality gap for people with severe mental illness.
Sarah Holloway, Chief Executive Officer of Maudsley Charity, said:
For too long, we have accepted early deaths of people with severe mental illness, but they are preventable. Two thirds of the public agree that better healthcare needs to be provided to improve the life expectancy of those with SMI, and that includes proactive physical health screening and basic reasonable adjustments in all physical health services and pathway. We are committed to working with partners to spread and scale what we know works in reducing premature deaths for people with SMI, in South London and beyond.
Professor Bobby Duffy, Director of the Policy Institute at King’s College London, said:
The public now consider mental ill health to be as serious a national health problem as cancer, and their top individual health concern – but 45% think our health services still give priority to physical health conditions. The public instinctively get the deep connection between physical and mental health, with three-quarters saying they consider both equally important in their own lives – but so often these connections are not reflected in health services. The real causes of the shockingly shorter life expectancies of people with severe mental illness are not, as the public believe, suicide or alcohol and drug abuse, but are instead related to physical conditions not being diagnosed or treated among this group, alongside lifestyle factors and the impact of medications. The key to better outcomes is to recognise and prioritise that connection.
Dr Siobhan Gee, consultant pharmacist, South London and the Maudsley NHS Foundation Trust, said:
The most important message we can get across is that this health crisis for people living with severe mental illness is not only hidden but it is preventable. We know it is vital to proactively manage the risk of developing physical illnesses from the onset of a severe mental illness, and to treat physical conditions effectively if they occur. There is also compelling evidence that using the most effective medicines to treat the symptoms of serious mental illness can halve the risk of premature mortality from physical disease.