A mental health issue isn’t “all in your mind.” The mind arises from the brain, and the brain is a part of your body that closely interacts with the rest of your body.
This was from a study of 68,000 adults ages 35 and over in the U.K.:
Their results reveal that people who experienced symptoms of anxiety or depression had a lower life expectancy than those without any such symptoms.
Even people with minor symptoms of mental health problems seemed to have a higher risk of death from several major causes, including cardiovascular disease, according to the researchers.
And it’s not just a matter of poorer health behaviors. The researchers did try to control for factors like weight, eating habits, exercise, drinking, etc. and still found associations between these mental health symptoms and disease. (Granted they didn’t control for all possible factors, but they did try to account for some basic lifestyle choices that strongly impact health.)
Having poorer mental health doesn’t automatically doom you to a shorter life. No one can say what your individual outcome will be. What the study is showing is that on average people with poorer mental health have a shorter life expectancy compared to people with good mental health. As a preventative measure, to increase the odds in your favor that you’ll live longer and with a higher quality of life, don’t ignore your psychological distress or any other symptoms indicative of poor mental health. The effects ripple out to all areas of your life.
Here’s a post with some comments from a few researchers and doctors on the study in the first link; the post includes some comments on potential weaknesses in the study and what can be researched next (for instance, what are the best interventions?). There are multiple ways that psychological distress can be linked to poorer health and shorter lifespan. Chronic stress damages the body and increases the chances of physical illnesses. People with poorer mental health might be more isolated and have less of a social support network. Maybe when they’re physically healthy they can get by, but when they come down with a physical illness they may neglect to get it treated. This is a fruitful area of research.