If you’re one of the millions of Americans who lives with a mental disorder, your body might be older than you think.

New research—presented last weekend at the European Congress of Psychiatry in Paris—shows that those with longstanding mental health conditions like depression, anxiety, and bipolar disorder are biologically older than their actual, chronological age.

Researchers Dr. Julian Mutz and Cathryn Lewis, both with the King’s College London, looked at the blood metabolites—small molecules produced during the process of metabolism like lipids, cholesterol, and amino acids—from more than 110,000 U.K. residents. They found that those with mental illness had a “metabolite profile” that indicated they were older than they actually were.

“For example, people with bipolar disorder had blood markers indicating that they were around two years older than their chronological age,” Mutz says in a release ahead of the presentation.

The findings complement earlier research by Mutz and others that found that those with mental health disorders tend to live shorter lives and have more health issues, like diabetes and heart disease. A 2002 study by Mutz found that those with anxiety, depression, and bipolar disorder were more likely to be medically frail, a condition associated with a higher risk of death.

People with severe mental health conditions may die as many as two decades early due to “preventable physical conditions,” according to the World Health Organization.

The research highlights the opportunity for doctors to track the metabolite profiles of patients with mental disorders, and to use changes in such profiles to gauge the effectiveness of health interventions, Mutz says.

How to slow biological aging

Fortunately, there are steps patients can take to slow their biological aging, Mutz tells Fortune. Things that contribute to faster biological aging in people with mental illness include:

 Physical inactivity

 Smoking

 Overreaction of autonomic nervous system

 Chronic low-grade inflammation

 Social isolation/loneliness

“These factors are known to have a negative impact on health, and addressing these risk factors would be beneficial,” he says. Some actions those with mental disorders might take to slow their biological aging include:

 Increasing physical activity, perhaps with regular strength and resistance training

 Quitting smoking, if applicable

 Forming and maintaining positive relationships

Such lifestyle changes are likely to reduce mental health symptoms as well. They will, however, “be difficult to achieve for people who are severely unwell,” he adds. “Treating their mental health symptoms—whether through psychological, pharmacological or other treatments—should always be considered alongside with their physician.”