Millions of Americans with mood disorders are eligible for booster shots. Here’s how depression raises the risk of severe COVID-19.

• People with schizophrenia, bipolar disorder, and major depression are eligible for booster shots.
• Having a mood disorder is linked to increased risk for severe COVID-19 illness and death.
• Experts pushed to include mood disorders on the CDC’s list of conditions that put people at risk for severe COVID-19.

People who’ve been diagnosed with mood disorders like schizophrenia, bipolar disorder, and major depression are now eligible for COVID-19 booster shots, according to the Centers for Disease Control and Prevention.

The recommendation came weeks after the agency added mood disorders to its list of medical conditions that put people at greater risk for becoming severely sick with COVID-19 – a list that also includes obesity, diabetes, and pregnancy. Although mental-health providers and researchers have long asserted that mental health is as important to overall well-being as physical health, medical and insurance systems don’t always treat it as such – so the change wasn’t a foregone conclusion.

“I was really pleased that the CDC did this,” Dr. Roger McIntyre, scientific advisory board chair at the Depression and Bipolar Support Alliance, told Insider.

McIntyre said he’d reached out to the CDC after he saw that mood disorders weren’t included in the agency’s initial list of underlying conditions that raise one’s risk of severe COVID-19. He even sent psychiatry papers to support his position. McIntyre later learned that other psychiatry organizations had done the same.

The change significantly broadens the pool of Americans who are eligible for COVID-19 booster shots. An estimated 19.4 million adults in the US, or 7.8% of the population, had at least one major depressive episode in 2019, according to the National Institute of Mental Health.

Why people with mood disorders are at higher risk for severe COVID-19 illness and death

A meta-analysis that McIntyre co-authored and published in the journal JAMA Psychiatry last month found an association between pre-existing mood disorders and a higher risk of being hospitalized and dying from COVID-19. The research analyzed 21 studies and included more than 91 million people. It did not, however, find a link between those mental-health conditions and being more physically susceptible to contracting COVID-19 in the first place.

McIntyre explained that people who have mood disorders are more likely to have physical health problems, such as heart disease, diabetes, cardiovascular disease, or Crohn’s disease.

So people with mood disorders who also have a second diagnosis were already be eligible for booster shots. But statistically, those with schizophrenia, bipolar disorder, and depression, aren’t diagnosed for physical health conditions at the same rate as the general population.

“If you walk into a clinic, and you say to the nurse or the doctor, ‘I have schizophrenia, I have depression, I have bipolar disorder,’ they aren’t likely going to diagnose the other medical problems,” McIntyre said, adding, “It’s just a bias that we have in our medical system.”

In addition to a higher likelihood of physical health conditions, behavioral and social factors associated with mood disorders also increase the risk of severe COVID-19. People with mood disorders smoke cigarettes and use substances at higher rates than the general population and have less access to timely and reliable medical care, McIntyre said. They’re also more likely to live in congregate settings, such as homeless shelters, community housing, and prisons, which puts them at higher risk for contracting COVID-19 and having more severe outcomes from it.

Even people with mood disorders who do not live in congregate settings and are otherwise healthy still have an elevated risk. An article published in the journal Science last summer found a link between immune-system problems and a variety of psychiatric disorders, including depression, bipolar disorder, and schizophrenia.

“People who have mood disorders have some type of dysregulation in their immune system,” McIntyre said, adding, “even if you lived a perfect life and you had a mood disorder or schizophrenia, just that Mother Nature disorder is going to put you at risk.”