Study links stress hormone to higher depression risk

HIGHER levels of the stress hormone cortisol may increase the risk of developing depression, according to new research.

Researchers from The Irish Longitudinal Study on Ageing (TILDA) found that higher cortisol levels in older adults, measured from hair samples collected in 2014, were associated with an increased likelihood of depression during the early months of the COVID-19 pandemic, six years later.

Cortisol measured in hair is thought to reflect previous stress exposure as well as other biological and psychological factors.

Higher levels are sometimes found in people who are already depressed, but the new research suggests that cortisol, measured in this way, could also help

predict who is vulnerable to depression in the future, following a period of heightened stress.

The study of people aged 60 and over during the first year of the COVID-19 pandemic found that the results did not differ between men and women.

Dr Joanne Feeney, lead author of the study and Senior Research Fellow in Medical Gerontology at Trinity, says the research highlights a key benefit of longitudinal studies.

‘As TILDA has been gathering data for years, we were able to look back in time to 2014 to when cortisol levels were measured and investigate whether they were associated with an increased risk of depression during COVID-19.’ she says.

‘Given the negative impact of the virus and lockdowns on mental health, the findings are important for understanding who may be most at risk and thinking about possible protective measures for the future,’ adds Dr Feeney.