Commonly prescribed antidepressants called selective serotonin reuptake inhibitors (SSRIs) may raise a pill-taker's risk of suffering a stroke.
A new study found the overall risk of a stroke for people taking antidepressants remains low, but the researchers warn that patients at risk for stroke may want to consider an alternative depression treatment.
"Overall, these results should not deter anyone from taking an SSRI when it is needed," study author Dr. Daniel G. Hackam, an assistant professor of clinical pharmacology, clinical neurological sciences, and epidemiology at Western University in London, Ontario, said in a press release.
Popular SSRI drugs include Prozac, Zoloft, Paxil and Lexapro. They work by blocking the reuptake of a brain chemical called serotonin, which affects people's mood and emotional responses. The drugs have long been considered safer than older antidepressants which may cause side effects.
Hackam and his team reviewed 16 studies with more than 500,000 total participants for the new research, which is published in the Oct. 17 issue of Neurology. They found that people taking SSRIs were 50 percent more likely to have an intracranial hemorrhage than those not taking antidepressants and a 40 percent elevated risk for having an intracerebral hemorrhage.
Those are two types of hemorrhagic strokes, which occur when a blood vessel in part of the brain becomes weak and bursts open, cause blood to leak into the brain. The most common type of stroke however is an ischemic stroke, caused by a blood clot that blocks a blood vessel in the brain, which accounts for 85 percent of all strokes.
"Because these types of strokes are very rare, the actual increased risk for the average person is very low," Hackam said.
According to the study authors, 24.6 of these types of strokes occur per 100,000 people per year. The added stroke risk for antidepressants accounts to one additional stroke per 10,000 people per year.
SSRI drugs slow down the rate of blood clot formation, which may explain the link found in the study, WebMD reported.
Hackman also told Reuters that people taking SSRIs may also have habits or health issues that put them at a greater stroke risk.
"They can tell us there is a correlation, but that doesn't necessarily mean that there is a causal connection," Dr. Jordan Smoller, associate professor of psychiatry at Harvard Medical School who was not involved in the study, told WebMD.
Hackam said doctors may want to consider using other types of antidepressants for people at higher risk for stroke, such as those taking blood thinners, people who have already had strokes or those with a history of alcohol abuse.
"We should remember that the conditions people take SSRIs for -- depression and anxiety -- have their own risks in terms of adverse health outcomes, suffering, disability, and even suicide," Smoller added. "So it's not a matter of risk versus no risk."