Deprivation and transport density linked to increased suicide risk in England

A groundbreaking study led by researchers at Imperial College London, UCL, and the London School of Economics and Political Science (LSE) examined suicide trends in England from 2002 to 2022, focusing on the impact of local socio-environmental factors on risk.

An analysis of national mortality data over the 20-year period revealed that areas with higher levels of social deprivation and increased rail and road network density were associated with elevated suicide risk. Conversely, higher levels of ethnic diversity, population density, light pollution, and green space were linked to a reduced risk. However, the study did not delve into the method of suicide.

Although the overall suicide rate in England remained stable at around 11 deaths per 100,000 people from 2002 to 2022, significant regional variations were observed. The North-East of England had the highest relative risk values (14.48% above the national average), while London had the lowest risk (17.74% below the national average), resulting in a 39.2% difference between the highest and lowest risk regions.

The researchers emphasized the importance of local social and environmental factors in influencing suicide risk, suggesting that their model could provide valuable insights into local risk factors and aid in the development of targeted prevention strategies at the national and regional levels.

The study was published in the journal The Lancet Regional Health—Europe.

Dr. Connor Gascoigne, the study’s first author from Imperial’s School of Public Health, highlighted the implications of the findings, stating, “Our analysis indicates that individuals residing in deprived and isolated areas may face an increased risk of suicide, while certain social factors appear to have a protective effect. By tracking these factors over time, we can better understand their impact on suicide risk and shape effective policies.”

The researchers underscored the need for improved regional services focused on prevention and emphasized the urgency of national policies to address regional inequalities across the UK.

National Suicide Trends

Each year in the UK, an average of 6,300 suicide deaths occur, equivalent to 11 per 100,000 people. While individual risk factors for suicide such as mental illness, substance use, or chronic pain are well-known, less is understood about local-level risk factors and their evolution over time.

The study analyzed suicide death data in England from 2002-2022, covering 6,791 administrative areas, each with up to 15,000 residents. The researchers combined this data with socio-environmental factors predicted to influence suicide risk at the local level, including measures of deprivation, ethnic density, population density, light pollution, railway network density, road network density, and green space.

Although the national suicide rate remained relatively stable over the period, with minor fluctuations around an average of 11 deaths per 100,000 people, there were year-on-year variations in relative risks for England. The study also compared suicide rates in England and Wales, reporting a consistent 11.0 suicides per 100,000 population over the same period.

Dr. Gascoigne emphasized that while the study found no significant change in the national suicide rate, it does not diminish the importance of existing services and efforts to prevent suicide-related deaths. The findings may indicate that current policies have helped mitigate the impact of significant events like the COVID-19 pandemic.

The researchers hope that their approach will provide crucial evidence for monitoring environmental factors over time to protect vulnerable individuals and reduce suicide risk in England.

Regional Suicide Trends

Regionally, the North East and North West of England consistently exhibited higher suicide rates than the national average over the 20-year period, with averages of 14.48% and 11.42%, respectively. The South West also had a consistently higher-than-average suicide rate (9.76%), while London consistently had a rate below the national average (-17.74%), with a 39.2% lower suicide risk compared to the North East of England.

When examining the impact of environmental factors on suicide risk, the researchers found that increasing levels of deprivation, road network density, and railway network density were associated with higher suicide risk. Conversely, suicide risk decreased with higher ethnic density, population density, reduced light pollution, and increased green space.

The study acknowledged several limitations, including the focus on England only and the lack of detailed information on deceased individuals beyond age and sex. The researchers stressed the need for policy changes to address regional disparities and reduce suicide rates in England.

Professor Marta Blangiardo, the senior author of the study, emphasized the impact of social deprivation on community health, emphasizing the need for targeted interventions to reduce regional inequalities and improve public health outcomes.

Professor Alexandra Pitman, a study co-author from University College London, highlighted the importance of understanding spatial influences on suicide risk to enable effective preventive measures at the local level. She emphasized the need to investigate how environmental factors contribute to suicide risk and how interventions can be tailored to address these risks.

Niall Boyce, Head of Knowledge and Measurement in Mental Health at Wellcome, underscored the value of scientific research in identifying complex associations between environmental factors and mental health, ultimately guiding the design and delivery of interventions for those in need.