Researchers examined data from all deaths Danish residents ages 18 to 90 during 2010. Of those deaths, researchers divided the group into those who used antidepressants and those who didn’t. Of the 6,002 sudden cardiac deaths—an unexpected death caused by a heart-related issue—in the population, they found that the prevalence of sudden cardiac death was much higher in those who took antidepressants than those who didn’t, when adjusted for age, sex, and comorbidities. The exception was those ages 18 to 29, however, for whom the association between cardiac death and antidepressants was not statistically significant.

Within the group who took antidepressants, researchers further split them into two groups based on exposure time: people who took the medication for one to five years, and those who took it for six years or more. The group that took antidepressants for one to five years had a 56% higher risk of sudden cardiac death, while those using antidepressants for six or more years had a 2.2 times higher risk than those who were not on antidepressants at all. 

“Exposure time to antidepressants was associated with a higher risk of sudden cardiac death, and linked to how long the person had been exposed to antidepressants,” study co-author Dr. Jasmin Mujkanovic of Rigshospitalet Hjertecentret, Copenhagen, Denmark, said in the press release. “Those exposed for six years or more were at even more increased risk than those exposed for one to five years, when compared with people unexposed to antidepressants in the general population.”

Several classes of antidepressants were represented in the study, but researchers did not link specific drugs to specific health outcomes.

Cardiac risk varied by age group

Researchers found that the risk of a sudden cardiac death varied based on age: 

• Ages 30 to 39: One to five years of antidepressant use were around three times more likely to suffer sudden cardiac death. Risk increased to five times higher for those with six or more years of exposure.
• Ages 40 to 49: One to five years of antidepressant use had about a 1.6 times greater risk, while those with six years or more of exposure had their risk tripled.
• Ages 50 to 59: One to five years of antidepressant use had their risk doubled, while individuals exposed to antidepressants for six or more years had four times the risk.
• Ages 60 to 69: Nearly double the risk for those using antidepressants for one to five years, and about 2.6 times higher for those exposed for six or more years.
• Ages 70 to 79: Those with one to five years antidepressant exposure had nearly double the risk, while those with six years or more of exposure had a 2.2 times increased risk.

Why antidepressants may be linked to cardiac death risk

Mujkanovic posits there could be multiple reasons why sudden cardiac death risk was higher among those taking antidepressants. For one, it could be the drugs themselves causing the adverse effects, he said in the press release.

Previous research has found a connection between a class of drugs called tricyclic antidepressants and heart disease and stroke. 

“However, the exposure time to antidepressants might also serve as a marker for more severe underlying illness,” he said.

Other research has also pointed to depression itself as a risk factor for cardiovascular disease. 

“Additionally, the increase could be influenced by behavioral or lifestyle factors associated with depression, such as delayed healthcare seeking, and poor cardiovascular health,” he added. 

“Further research is warranted.”

Are antidepressants safe?

While there are several classes of antidepressants, the most commonly prescribed are selective serotonin reuptake inhibitors (SSRIs):

• Citalopram (Celexa)
• Escitalopram (Lexapro)
• Fluoxetine (Prozac)
• Paroxetine (Paxil)
• Sertraline (Zoloft)

Though generally considered safer than older classes of antidepressants, SSRIs, like any medication, may interact with other drugs and supplements you’re taking. They also come with side effects and risks. 

It’s best to talk to your doctor to weigh the benefits and risks of taking antidepressants.

For more on mental health:

• Almost 1 in 2 Americans feel they’ve lost time to poor mental health, survey says. It’s worse for people with depression or anxiety
• Stigma keeps many men from seeking mental health support. These 3 shifts in thinking can help
• Opening up about his anxiety and depression helped this former Google executive be a better leader
• American families have an increasingly bleak outlook, and 4 factors are driving their gloom