Most Britons unaware of extent to which severe mental illness cuts lives short
Read the research
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.
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 SMI disproportionately affects Black communities and urban populations.
There is broad support for improving healthcare for those with SMI, with two-thirds (67%) saying more needs to be done to improve life expectancy among this group.
However, public opinion is 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 due to a recent loosening of the national mental health investment standard, which has previously protected expenditure in mental health.
The research comes ahead of a roundtable on 12 November, King's Health Partners 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.
King's Health Partners is formed of three NHS foundation trusts - Guy's and St Thomas, King's College Hospital, and South London and Maudsley - together with leading university King's College London. Maudsley Charity, which funded the research, is a leading funder of mental health care projects in south London, and the charity partner for South London and Maudsley. King's Health Partners and Maudsley Charity are partnering to promote positive change in the world of mental health.
The public are not aware of the leading cause of death among people with SMI
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.
Few realise the inequalities in which groups or areas are most affected by SMI
- Just 14% of the public correctly recognise the prevalence of SMI is higher among Black African and Black Caribbean British communities. This compares with 49% who believe there is no real difference between Black and White people and 13% who think it is more common among White British people.
- A higher proportion of people - 27% - are correct that SMI rates are higher in urban, rather than rural, areas, but the most common answer is that there is no real difference between the two, selected by 46%.
- The public are however most likely to correctly think SMI is more common among those living in deprived, rather than better-off, areas. 43% hold this view, compared with 34% who say levels of deprivation don't make much difference.
The public say better healthcare is needed to treat people with serious mental illness
Half the public (50%) believe those with SMI do not get the help they need - double the proportion (25%) who say the opposite.
And two-thirds (67%) agree better healthcare needs to be provided to improve the life expectancy of those with SMI.
…but there are doubts about feasibility and whether it should be prioritised
A third (33%) of the public feel it is not too challenging to provide the healthcare needed to improve the life expectancy of those with SMI, while virtually the same proportion (30%) feel it is too difficult.
Opinion is similarly split on whether there are (28%) or are not (33%) more urgent priorities for the healthcare system than the life expectancy of people with SMI.
Younger adults aged 18 to 34 are around twice as likely (39%) as over-55s (21%) to say there are more urgent priorities for the healthcare system, as well as being more likely to say it is too challenging to provide the care needed.
Mental health is tied with cancer as the biggest perceived health problem
More generally, mental health and cancer are now tied as the biggest perceived health problem facing the nation, with 45% and 44% respectively listing it among their top three concerns.
And there is a gender divide in views, with women (52%) more likely than men (38%) to select mental health as a key challenge.
Mental health is also the biggest health concern on an individual level, with one in four (26%) saying they are personally concerned about their own mental health, followed by arthritis or back problems (22%) and cancer (17%).
Most see mental and physical health as equally important, but they're not convinced the healthcare system treat them this way…
Seven in 10 (72%) people say they regard physical and mental health as equally important, while 15% say physical health should take precedence and 10% say mental health.
However, people are still most likely to feel physical, rather mental, health is treated as more important in the healthcare system. 45% hold this view, compared with 33% who say mental and physical health have parity in the system and just 9% who think mental health is treated as more important.
…even if there has been a shift in perceptions of how they are dealt with
Despite this, the share of the public who feel mental and physical health are treated equally in the healthcare system has risen from one in five (20%) in 2019 to one in three (33%) today.
Over the same period, the proportion who say physical health is treated as more important has fallen from 64% to 45%.
These perceptions have changed even though mental health only amounts to 8.8% of total NHS expenditure. And while the proportion of NHS spending on mental health has increased since 2021, it is expected to fall slightly in 2025/26. This comes as mental health is the biggest cause of lost work days in the UK and globally.
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."
Study details
Opinium surveyed 2,000 UK adults aged 18+, between 7 and 10 October 2025, via an online access panel. Data is weighted by age, gender, ethnicity, region, social grade and working status in order to reflect the profile of the UK population.
King's Health Partners is formed of three NHS foundation trusts - Guy's and St Thomas, King's College Hospital, and South London and Maudsley NHS - together with leading university King's College London. Maudsley Charity, which funded the research, is a leading funder of mental health care projects in south London, and the charity partner for South London and Maudsley. King's Health Partners and Maudsley Charity are partnering to promote positive change in the world of mental health.
