An analysis of suicide rates in England has shown how factors like deprivation and transport density are linked to regional increases in suicide risk.
The first of its kind study, led by researchers at Imperial College London, UCL and the London School of Economics and Political Science (LSE), looked at suicide trends in England from 2002 to 2022 combined with the influence of local socio-environmental factors on risk.
In an analysis of national mortality data over the 20-year period, they found that local areas with higher levels of social deprivation, as well as increased rail and road network density, were linked with an increased suicide risk. Higher levels of ethnic diversity, population density, light pollution and green space, were linked with a lower risk. However, the study did not consider method of suicide.
While there was no significant change in the overall suicide rate in England from 2002-2022 (which remained around 11 suicide deaths per 100,000 people), the study found significant variations in regional suicide risks – with the highest relative risk values in the North-East of England (14.48% above national average), and the lowest risk in London (17.74% below national average) – with a difference of 39.2% between the highest and lowest risk regions (using an average of year on year comparisons).
According to the researchers, the work helps to highlight the role of local social and environmental factors on suicide risk. They explain that their model could be used to bring new insights into local risk factors for suicide and identify higher risk areas which could ultimately help to improve and target national and regional prevention strategies.
They add that the work aligns with the goals of the recently published NHS 10-Year Health Plan, promoting prevention and early intervention and a commitment to reducing the number of lives lost to the biggest killers, including suicide.
The study, published today in the journal The Lancet Regional Health - Europe, was supported by funding from Wellcome Trust, UK Health Security Agency, UKRI Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR).
Dr Connor Gascoigne, from Imperial's School of Public Health and first author of the study, said: "Our analysis suggests that people living in deprived and isolated areas may have increased risk of dying from suicide – while some social factors have a seemingly protective effect. While many of these risk factors are well established, our methods could be used as a tool to track how these factors change over time and their impact on suicide risk and inform policy.
"We know inequalities can have huge and lasting impacts on people's health, but also on suicide risk. This work highlights not only the need for improved regional services focused on prevention, but also that national policies are urgently needed to reduce regional inequalities across the UK."
National suicide trends
Each year in the UK there are an average of 6,300 suicide deaths, equivalent to 11 per 100,000 people. While individual risk factors for suicide are complex and variable, such as mental illness, substance use or chronic pain, they are well-recognised. But much less is known about local level risk factors for suicide and how they change over time.
In the latest study, researchers analysed data from the Office for National Statistics (ONS) on suicide deaths in England from 2002-2022. These data covered 6,791 administrative areas in England, each containing up to 15,000 people. The team used date of death, rather than the date the cause of death was registered as suicide – the latter often delayed due to coroners' investigations and reports. Details of suicide method were not captured in the model.
The team combined these data with information on socio-environmental factors they predicted might be associated with suicide risk at the local level. These included measures of deprivation, ethnic density, population density, light pollution, railway network density, road network density, and green space.
Analysis of the national trend over time found that there was no significant change from 2002-2022 (with variations around an average of 11 suicide deaths per 100,000 people over the period), but there were year on year fluctuations in relative risks for England – with a low point in 2007 and a peak in 2019 (with Relative Risks of 0.92 and 1.09, respectively). Similar results have been reported where England and Wales have seen a consistent 11.0 suicides per 100,000 with a change from 9.0 to 10.9 per 100,000 from 2002 to 2022.
Dr Gascoigne, who carried out the analyses at Imperial's MRC Centre for Environment and Health, added: "It's important to stress that while our study found no significant change in the national suicide rate between 2002-2022, this by no means negates the existing services in place and the efforts of those working to help people at risk and to reduce deaths from suicide. Indeed, it may show that such policies have helped to buffer the impacts of significant national and global events, such as the COVID-19 pandemic.
"We do hope that our approach could provide crucial evidence-informed approach to monitoring the impact of such environmental factors over time, to better protect vulnerable individuals and reduce suicide risk in England."
Regional suicide trends
Regionally, the North East and North West of England had higher suicide rates than the national average across the 20-year period (an average of 14.48% and 11.42%, respectively). The South West also had a consistently higher than average suicide rate across most years (9.76%). London was the only region where the rate was below the national average for all years (-17.74%), with suicide risk in London 39.2%[1] lower than in the North East of England overall.
When modelling the impact of environmental factors on suicide risk, the researchers found that for each standard deviation increment in the predictor investigated, suicide risk increased with deprivation (20.06%), road network density (5.16%) and railway network density (1.37%). But suicide risk decreased with ethnic density (-7.47%), population density (-5.42%), light pollution (-4.20%), and greenspace composition (-6.43%).
The researchers highlight several limitations to the study, including that the data only cover England, as well as the limited detailed information available on the deceased individuals – while data on age and sex were available, they were unable to identify ethnicity, or information on other factors such as family structure, employment or socioeconomic status.
Professor Marta Blangiardo, from Imperial's School of Public Health and senior author of the study, said: "The health and social impacts of social deprivation on communities in the UK are well established. We know that people in poorer regions of the country, with fewer job opportunities and fewer public services, have stark differences in life expectancy and health compared to those living in the least deprived areas of the country. This rings true in our analysis.
"While any number of complex individual factors can increase a person's risk of death by suicide, we find that local factors – such as living in an isolated area or a heavily industrialised area with greater deprivation – may have a significant impact on an individual's suicide risk. These findings should help to inform and drive policy changes to further reduce suicide rates in England, in line with the goals of the NHS Long Term Plan."
Professor Alexandra Pitman, Professor of Psychiatry at University College London, and study co-author, said: "There is a lot of policy interest in understanding spatial influences on suicide risk because of the potential for local authorities to address these factors at the area level and reduce suicide risk for a large number of people in their populations.
"We know there is a well-established association between social deprivation and suicide risk, and we can understand why, so our finding that area-level deprivation was associated with suicide may not be that surprising. However, our finding that factors such as greater road network density and railway network density were associated with higher suicide risk, and that greater light pollution are associated with higher suicide risk are striking. We need to understand how these pathways operate in order to work out how to intervene to reduce risk.
"To take the example of transport network density, it is possible that roads and railway lines create noise or air pollution, which was why we were keen to investigate this as a potential influence on suicide risk. However, transport lines can also carve physical barriers through communities or provide access to the means of suicide, and these might explain the increased risk instead. We should also take into account that having better transport connectivity to others might improve mental health and reduce suicide risk. This example shows that a study of this kind is valuable in identifying important macro-level patterns, directing our focus on understanding how preventive efforts might operate and how they might best be delivered."
Niall Boyce, Head of Knowledge and Measurement in Mental Health at Wellcome said: "These findings illustrate how scientific research can help us to untangle some of the complex associations between environment and poor mental health. Ultimately, better understanding of these factors will help us to design and deliver interventions to those who need them, at the earliest possible stage."
Professor Sir Louis Appleby, from the University of Manchester and Chair of the National Suicide Prevention Strategy Advisory Group, who was not involved in the research, said: "A lot has happened to suicide rates in England & Wales in the last 20 years. A long-term fall culminated in 2007 in the lowest rate on record. The 2008 global recession put rates up, the global pandemic did not. After 2008 the pattern of suicide changed – middle aged men were now the group at highest risk and a gap opened up between London and other regions, especially the North-East. Rates in young people rose steadily, though have now levelled off.
"In 2018 a new standard of proof led to a jump in suicide conclusions at inquest – with national data, definition is everything and figures pre- and post-2018, as in this study, may not be strictly comparable. These new findings too remind us that suicide rates are complex, reflecting how and where we live, frequently changing. They show the breadth of measures that any national prevention policy should embrace, and the need for constant vigilance."
The work was supported by the NIHR through its Health Protection Research Units (HPRUs) at Imperial College London in Environmental Exposures and Health and in Chemical and Radiation Threats and Hazards, and through Health Data Research UK (HDR UK) in the Social and Environmental Determinants of Health Driver Programme.
The work at Imperial was also underpinned by infrastructure support from the NIHR Imperial Biomedical Research Centre, a translational research partnership between Imperial College Healthcare NHS Trust and Imperial College London.
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'Spatio-temporal trends and socio-environmental determinants of suicides in England (2002 – 2022): an ecological population-based study' by Gascoigne, C., Jeffery, A., Rotous, I., et al. is published in The Lancet Regional Health - Europe. DOI: 10.1016/j.lanepe.2025.101386
