People who take antidepressants are at an increased risk of developing small, first-time brain bleeds, called cerebral microbleeds, according to a new longitudinal study published in the journal Stroke.
Cerebral microbleeds are generally associated with aging, dementia, and cerebrovascular disease. They may predict future brain hemorrhage risk, and may contribute to cognitive impairment, dementia and depression.
Researchers noted that the associations were similar for different categories of antidepressants users, and persisted even after adjusting for depressive symptoms and cardiovacsluar risk.
For the new study, researchers evaluated 2,550 people age 45 years and older who did not have a history of microbleeds at the beginning of the study. The median age of participants was 58.7 years and 54.8 percent were women, and the study was conducted between 2005 and 2013.
Study participants underwent a brain MRI at the start of the study and had a second MRI roughly four years later. The overall incidence of cerebral microbleeds was 3.7 percent, with patients taking antidepressants having a greater risk of developing the condition. Researchers found similar microbleed risk between SSRIs and non-SSRIs.
SSRIs, or selective serotonin reuptake inhibitors, are commonly prescribed antidepressants and include the brand name drugs Paxil, Zoloft, Lexapro, Celex and Prozac.
Researchers said the increased risk of microbleeds with SSRIs may be linked to a mechanism similar to that of blood thinner drugs, by which SSRIs “block the reuptake of serotonin by platelets and decrease serotonin platelet concentration, which may lead to impaired aggregation and prolonged bleeding times,” the authors noted.
Researchers say the findings suggest that caution should be used when treating depression in patients who may be at risk for microbleeds.