A new Canadian-led study has found that feeling depressed, along with living in a disadvantaged neighbourhood, may lead to premature aging.

The peer-reviewed study, published on Monday in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences, points to how depression and living in an urban environment – with greater material and social inequities – can influence how a person ages.

Led by researchers at McMaster University in Hamilton, Ont., the study's authors say this may occur "even after accounting for individual-level health and behavioural risk factors, such as chronic conditions and poor health behaviours."

"This adds to the growing body of evidence that living in urban areas with higher levels of neighbourhood deprivation and having depression symptoms are both associated with premature biological aging," team lead Parminder Raina, a professor in the Department of Health Research Methods, Evidence, and Impact at McMaster University, said in a news release.

The researchers used epigenetic data from 1,445 people enrolled in the Canadian Longitudinal Study on Aging, a long-term study that follows about 50,000 participants between the ages of 45 and 85 for at least 20 years.

The study is described as examining how changing biological, medical, psychological, social, lifestyle and economic factors impact a person's health as they age.

Epigenetics is the study of how behavior and environment can influence how a person's genes work.

The researchers measured depression symptoms using a standardized 10-item scale.

They say a one-point increase in the score accelerated a person's risk of death by one month, with the theory being that emotional distress caused by depression could lead to "more biological wear and tear and dysregulation of physiological systems."

In order to measure "neighbourhood material and social deprivation," the researchers used a pair of indices, based on the 2011 census, from the Canadian Urban Environmental Health Research Consortium.

They described material deprivation as a person's inability to obtain resources such as adequate housing, nutritious food, a vehicle, high-speed internet or recreational facilities, while social deprivation refers to family and community connections.

The researchers say greater neighbourhood deprivation increased a person's "risk of death by almost one year," but did not worsen the effect that depression had on aging.

In other words, both were independently associated with premature aging.

"Our results showed that the effect of neighbourhood deprivation on epigenetic age acceleration was similar regardless of depression symptoms, suggesting that depression influences epigenetic age acceleration through mechanisms unrelated to neighbourhood deprivation," Divya Joshi, first author of the study and a research associate at McMaster University, said.

The research team also included members from the Netherlands, Norway and Switzerland.