Long Covid’s long shadow: The infection linked to rising depression and anxiety years later

The mental health effects of Long COVID may last far longer than many people realise — in some cases, up to three years after the initial infection, a major new study has found. 

The research, published in BMC Public Health, followed adults in Michigan who had PCR-confirmed COVID-19 and tracked their mental health over nearly three years. It found that people with Long COVID were significantly more likely to develop symptoms of depression and anxiety long after their infection.

What is Long COVID?

The study explains that many adults continue to experience “long-term health effects of SARS-CoV-2 infection, known as Long COVID.” It defines Long COVID as “an infection-associated chronic condition that occurs after SARS-CoV-2 infection and is present for at least 3 months as a continuous, relapsing and remitting, or progressive disease state that affects one or more organ systems.”

More than 200 symptoms have been linked to Long COVID, with fatigue, shortness of breath, pain and headaches among the most common. But this study suggests the psychological toll may be just as serious, and longer lasting.

The three-year mental health impact

The researchers examined adults who did not have depression or anxiety at the start of the study. They then checked in with them about 1.5 years and again three years after their initial infection.

Their conclusion is clear: “Long COVID was associated with higher risks of depressive symptoms… and anxiety symptoms… after 3 years of follow-up.”

Even after adjusting for age, income, education, pre-existing health problems and other factors, the link remained strong. People with Long COVID had 1.86 times higher risk of depressive symptoms after three years and 1.60 times higher risk of anxiety symptoms after three years

In simpler terms, a dults who had lingering COVID symptoms were far more likely to struggle emotionally years later.

The gap widens over time

One of the most worrying findings was that the mental health gap between people with and without Long COVID actually grew over time. At the three-year mark: 16.9% of adults with Long COVID reported depressive symptoms, and only 7.5% of those without Long COVID did. 
 
As for anxiety, 17.2% of adults with Long COVID reported symptoms, and 9.3% of those without Long COVID did. 
 
The researchers observed that reporting of depressive and anxiety symptoms was “higher for both groups at the second follow-up,” but the increase was larger among those with Long COVID, widening the disparity.

Persistent or delayed symptoms

The study also looked at how symptoms evolved. It found that adults with Long COVID had “a 2.64 times higher risk of depressive symptoms at follow-up 2… relative to no depressive symptoms at either follow-up” They also had “a 2.48 times higher risk of anxiety symptoms at both follow-ups… relative to no anxiety symptoms at either follow-up.”

This means some people developed depression later, while others experienced anxiety consistently over time.

Most importantly, the study excluded people who already had depression or anxiety at the beginning, reducing the chances that pre-existing mental health problems explained the findings.

“Our findings that Long COVID is associated with higher depressive and anxiety symptoms after 3 years of follow-up highlight the need to monitor the mental health of adults with Long COVID,” the researchers conclude

Global long Covid burden

Long COVID has become one of the biggest health challenges to emerge from the pandemic. Research from around the world shows that about 6 to 10 out of every 100 people who get COVID-19 continue to have symptoms for at least three months. The risk is higher for those who had severe illness or were infected more than once.

Taken together, these findings suggest that hundreds of millions of people worldwide may now be living with Long COVID. 

Similarly, a brief communication published last year in NPJ Primary Care Respiratory Medicine highlights the enormous financial toll of Long COVID, estimating that ongoing symptoms after infection drain about $1 trillion from the global economy every year, roughly 1% of the world’s GDP.

The researchers drew on findings from multiple studies and reports to assess how Long COVID affects national economies, healthcare systems, workforce participation, and overall quality of life.

Estimates of how common Long COVID is differ significantly. More cautious projections place prevalence between 2% and 7%, while a large systematic review of 144 studies published up to 2024 reports a much higher figure of 36%, with greater risk seen among hospitalized patients, adults, and women.

"One economic model suggests $3.7 trillion in annual losses associated with long COVID, with 59% attributed to decreases in quality of life and the remaining losses attributed to reduced earnings and increased medical expenses," says this report.

Expert speak

Damini Sharma, a counselling psychologist based in Delhi, explains that physical and psychological health are deeply interconnected. According to her, any chronic condition, including Long COVID, can increase vulnerability to depression and anxiety if not properly managed. “When someone suddenly develops a long-term illness, their entire sense of normalcy is disrupted. There are more hospital visits, more follow-ups, and even basic activities like breathing, walking, or working can become exhausting,” she says. This ongoing strain, she notes, naturally takes an emotional toll.

She adds that the broader trauma of the pandemic has compounded this distress. Many people faced losses of loved ones, jobs, financial security, and stability, while also coping with lingering health issues. “A lot of people never really got the time to process what happened,” Sharma says. She explains that during the immediate crisis, people were in survival mode. “But once life started appearing ‘normal’ again, that’s when suppressed stress and anxiety began surfacing.” For some, symptoms that were muted during the fight-or-flight phase may now be intensifying years later.

Living with persistent fatigue and pain can further deepen psychological distress, she explains. A person who was once active and independent may now struggle with routine tasks. “You start comparing yourself to a version of you that no longer exists,” she says. Over time, this can lead to irritability, social withdrawal, disrupted sleep, and appetite changes, either sleeping too little or excessively, eating less or more than usual. Families, she advises, should watch for these shifts. “These aren’t signs of laziness. They can indicate that the person needs psychological support.”

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS