• source https://www.colorado.edu/today/2026/04/08/mental-physical-illnesses-often-go-hand-hand-genetic-study-helps-explain-why
  • by Lisa Marshall
  • For centuries, mental illness and physical disease have been viewed as two distinct categories …
  • … study of nearly two million people, published in the journal Nature Communications,
  • surprising finding here is not that psychiatric disorders and medical disorders are linked, but rather, how much they are linked,”
    • “At the genetic level, we found that there is so much overlap they are really not two different classes of diseases at all.” — Andrew Grotzinger
  • Grotzinger’s previous research has shown that people with one psychiatric disorder often have many (41% meet the criteria of four or more), …
    • Physical disorders also come in groups, with 38% of the global population having two or more chronic conditions.
  • … psychiatric disorders increasing risk of some physical disorders by nearly 400%.
  • People with depression, studies show, are 1.5 times as likely as those without depression to develop heart disease.
  • … rarely see someone with just one condition walk into a room,” said first author Jeremy Lawrence, a doctoral candidate in clinical psychology.
    • “If we can better understand the cross-talk between these conditions, we can do a better job helping the whole patient.”
  • ADHD, it had more in common, genetically, with physical diseases than with other psychiatric diseases.
  • Some specific diseases tended to go together.
    • … schizophrenia tended to pair with gastrointestinal problems;
    • bipolar disorder tended to pair with genitourinary disorders and sleep problems.
    • Depression and anxiety tended to pair with cardiovascular disease.
  • … chicken or the egg?
    • … mental illness, like depression, could lead to behaviors—like eating poorly or leading a sedentary lifestyle—that precipitate poor physical health.
    • … cancer diagnosis, physical illness could boost risk of mental illnesses like depression.
    • … common chunk of DNA may independently boost risk of both a physical illness and a mental illness.
    • GLP-1 agonists—originally developed for diabetes, then prescribed for weight loss, and now showing promise for use in substance abuse disorders …
      • … how drugs meant for physical disease are making their way into the mental health realm.
    • Genetics could also be used to predict which groupings of diseases across the mental and physical spectrums a person is susceptible to so they can intervene early.
    • … research shows that addressing mental illness can go a long way in improving overall health, said Grotzinger. It could also help break down the silos between psychology and general medicine.
    • “… diagnose physical illness, but in many ways, we don’t have that for psychiatric disorders, so some have viewed them as more esoteric and less tangible,”
      • “Psychiatric disorders are just as real as any medical disease. Our findings help make that argument.”