The bodies of people with a history of mental illness such as depression, bipolar disorder, or anxiety disorders have blood markers that suggest they are older than their actual age.
This explains why people with mental disorders tend to have shorter life expectancy and more age-related illnesses than the general population.
That's the main conclusion of a study by Julian Mutz and Cathryn Lewis of King's College London, who analyzed data on 168 different blood metabolites from 110,780 participants in the UK Biobank. The work has been presented at the European Congress of Psychiatry, which is being held until next Tuesday in Paris (France).
The authors linked this data to information about whether people had a history of mental illness and found that those with a mental disorder had an older-than-expected metabolite profile for their age.
"It is now possible to predict people's age from blood metabolites. We found that, on average, those who had a history of mental illness throughout their lives had a metabolite profile that implied they were older than their actual age. For example, people with bipolar disorder had blood markers that indicated they were about two years older than their chronological age," Mutz explains.
People with mental health disorders tend to have shorter lifespans and poorer health than the general population. Estimates of the effect vary by mental health condition. Often, people with mental health problems show a greater tendency to develop heart disease and diabetes, and these conditions tend to worsen with age.
A 2019 study found that people with mental disorders had a shorter average life expectancy of 10 years for men and 7 years for women compared to the general population.
"The bodies of people with mental health problems tend to be older than would be expected for an individual their age. This may not explain all the difference in health and life expectancy between people with mental health problems and the general population, but it does mean that accelerated biological aging may be an important factor," Mutz said.
"If we can use these markers to track biological aging, this may change the way we look at the physical health of people with mental illness and how we evaluate the effectiveness of interventions aimed at improving physical health."
Sara Poletti, from the San Raffaele Hospital in Milan (Italy), highlights that this new study provides "a possible explanation for the higher prevalence of metabolic and age-related diseases in patients with mental illnesses".
"Understanding the mechanisms underlying accelerated biological aging could be crucial for the development of preventive and personalized treatments to address the increasing difficulty of integrated management of these disorders."
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