Published this month in JAMA Open Network, the study used health records from more than 260,000 people from the U.S. Department of Veterans Affairs.
The correlation, researchers found, was much stronger in people 65 and older. This could be the result of decades of strife — from having a psychiatric condition and the circumstances that can lead to psychiatric conditions — battering the immune system.
“There’s a lot of evidence to suggest that chronic stress, traumatic stress, and psychiatric conditions can actually accelerate cellular aging,” Aoife O’Donovan, an associate professor of psychiatry at the University of California, San Francisco and one of the study authors, tells Inverse. “It’s putting you at risk for appearing older biologically, and for your immune system, in particular, to function like the immune system of someone who’s older than you, and that’s certainly seen in patients with psychiatric disorders.”
What’s New — People with any psychiatric diagnosis were 3.7 percent more likely to develop a breakthrough infection of Covid-19, the researchers found. This was after researchers adjusted calculations to account for relevant factors more common to V.A. patients.
Among the types of diagnoses, non-alcohol substance abuse issues had the greatest correlation to breakthrough cases, increasing risk by 16 percent. This was not a surprise, says O’Donovan. Addiction causes people to increase risk-taking behaviors, and the pandemic created an environment where everything from hugging to eating at a restaurant was a risk-taking behavior.
Next were adjustment disorders — ones in which someone feels unusual stress or sadness in response to a life event, linked to a 13-percent increase in risk, followed by anxiety conditions (eight percent), bipolar disorder (seven percent) alcohol use disorder (five percent), depression (five percent), and post-traumatic stress disorder (three percent).
There was a stark difference when the results were broken up between subjects younger than 65 and older. Overall, people older than 65 who had a psychiatric diagnosis were five percent more likely to have a breakthrough Covid-19 infection than others of that age. The risk shot up for each condition, more than doubling for PTSD and increasing by sevenfold for people with bipolar condition.
For those under 65, the association with depression, PTSD, bipolar disorder, and alcohol use disorders was reduced to the point of being statistically insignificant.
People under 65 with psychotic conditions — ones like schizophrenia that involve a break from reality —were less likely to get Covid-19 post-vaccination, which O’Donovan chalks up to social isolation. This echoes an Israeli study of people with schizophrenia; they were less likely to get Covid-19 in general. That study’s authors partially attributed those results to social isolation as well.
But for those older than 65, psychotic conditions were highly correlated with the risk of a breakthrough infection, increasing risk by a whopping 26 percent.
The paper theorizes that “the vulnerabilities associated with psychiatric disorders may interact with the vulnerabilities associated with older age to confer greater risk for incident breakthrough infection.”
How They Did It — Researchers used the records of 263,697 fully vaccinated V.A. patients, 51 percent of whom had at least one psychiatric diagnosis. About 15 percent experienced a breakthrough infection.
Using data exclusively from the V.A. was not ideal, O’Donovan says. This group is not representative of the entire U.S. population. People who go to the V.A. are more likely to be of lower socioeconomic status, have several medical conditions, and live in a rural area. They are also generally older and almost all men.
However, “the V.A. did a very good job of gathering all of this information and releasing it quickly,” she says. Without that kind of real-time record-keeping, she says, it would be incredibly difficult to get this much information on a recent phenomenon (“breakthrough Covid-19” is a concept that didn’t exist 16 months ago).
And with so much data, researchers can make adjustments to diminish the effect of factors that would color the results.
The findings “are unlikely to be specific to Covid-19”
Another shortcoming: The V.A. generally sorts patients into two age categories: under 65 and older than 65, ubiquitous in government records because 65 is the start point for Social Security and Medicare. This meant it was impossible to see when the increased risk of getting a breakthrough infection for people with psychiatric conditions really begins.
“We’d know more if we had 10-year brackets,” says O’Donovan.
Why It Matters — The study is yet another piece of research indicating that psychiatric conditions impact the immune system, a finding that could be important for more than today’s issue du jour.
The findings “are unlikely to be specific to Covid-19,” says O’Donovan, “but are much more likely to generalize to other infections. An obvious issue is risk for the flu and prevention of the flu.”
These findings give reason to consider mental health when crafting responses to Covid-19 and other infectious disease outbreaks.
“This study adds to a body of literature that’s telling us that patients with psychiatric disorders may well be — and do appear to be — a vulnerable population in this pandemic that might need targeted prevention efforts,” says O’Donovan. “We may need to be focused on integrating Covid prevention into mental health care and also integrating mental health care into our Covid prevention strategies because the two are so interlinked.”
What’s Next — O’Donovan would like to embark on a project that investigates the effectiveness of Covid-19 vaccines on people with psychiatric conditions, one that might indicate an added need for boosters.