New research by the University of Essex, University of Manchester and the University of Singapore has found that people living with chronic pain who have lower levels of the stress hormone cortisol tend to recover their mental health better than those with higher levels of the hormone.
Using hair cortisol to measure the mental health resilience of people with chronic pain provides a new tool to identify higher-risk older adults who need mental health support. It could also help clinicians identify more resilient people with chronic pain, who may recover their mental health naturally.
The scientists used data from 3,000 older adults in the UK, who take part in the English Longitudinal Study of Ageing (ELSA) and Understanding Society. The analysis reveals a critical link between chronic pain, stress hormone regulation, and mental health resilience.
Cortisol is a stress hormone that is naturally elevated during prolonged exposure to physical pain. It can be measured using saliva and blood samples, but these only give a snapshot of cortisol levels at the time of the test. Using hair cortisol allowed researchers to study the effect of long-term stress, which accumulates over months and to see how this impacts people’s mental health over time.
Lead researcher, Professor Tarani Chandola at the University of Singapore, said: “Chronic pain isn’t just a psychological phenomenon- it has biological consequences. Having some stress in response to chronic pain is a normal human response. Some people adapt and show resilience with low cortisol levels, while others experience ongoing stress, with high cortisol levels predicting future mental health problems. Our findings help identify which older adults with chronic pain need support and who are likely to recover with less help.”
Co-author Professor Meena Kumari at the University of Essex said:
“Chronic pain affects over 1.5 billion people globally and often coexists with mental health disorders. Understanding more about who might be more susceptible to prolonged mental health problems and who is more resilient, could help clinicians better support people experiencing chronic pain.
Some people appear to have the natural ability to adjust to higher cortisol levels, such as those caused by chronic pain, in a way that minimises harm and maintains their level of physical and mental functioning.”
Key findings:
· Low cortisol levels (in the bottom 10%) are linked to resilience, with a 40% chance of depression recurring in older adults with chronic pain and depression.
· High cortisol levels (in the top 10%) indicate prolonged stress, with a 71% chance of depression recurring in older adults with chronic pain and depression.
· Moderate cortisol levels (between the 30th and 60th percentiles) are not associated with chronic pain, but people with these levels still have a similar risk of recurring depression as those with high cortisol, so this is not a healthy response.
The research was carried out by a team from the University of Singapore, University of Manchester and University of Essex. It is published in the journal Psychological Medicine.
Professor Meena Kumari added: “This new research is really valuable in the quest to understand how we help those living with chronic pain. Knowing how we react to cortisol is crucial.”
About the data used
ELSA (English Longitudinal Study of Ageing) is long-term study of the dynamics of health, social, wellbeing and economic circumstances in the English population aged 50 and older. The study tracked cortisol levels and depression over six years. https://www.elsa-project.ac.uk/
Understanding Society is the UK Household Longitudinal Study. The study interviews the same households in the UK each year about many aspects of life in the UK, including information about people’s health. https://www.understandingsociety.ac.uk/about/about-the-study/