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Certain Antidepressants Linked to a Slightly Smaller Risk of Stroke
MINNEAPOLIS鈥 Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants. Now a new study has found certain SSRIs and other antidepressants that increase serotonin levels in the brain the most may be associated with a reduced risk of ischemic stroke when compared to antidepressants that increase serotonin levels the least. The study is published in the August 7, 2019, online issue of 庐, the medical journal of the 好色先生. An ischemic stroke is when blood flow to part of the brain is blocked. Serotonin is a chemical that transmits signals between nerve cells in the brain. It is released from a cell when sending a signal and then is naturally reabsorbed back into the cells. These drugs inhibit the nerve cells from reabsorbing serotonin, thereby making more of it available in the brain, in the gaps between nerve cells, which improves the brain鈥檚 ability to regulate mood. 鈥淚t is not uncommon for people with depression to also have heart disease, a risk factor for stroke, so it is important to investigate whether antidepressants raise or lower the risk of stroke,鈥 said study author Christel Renoux, MD, PhD, of McGill University in Montreal, Canada. 鈥淲hile studies investigating stroke risk in people who take antidepressants compared to people who do not take them have found mixed results, our study took an even closer look, investigating stroke risk in people who take antidepressants that increase serotonin levels the most compared to people who take antidepressants that increase levels the least.鈥 For the study, using a database of more than 15 million people in the United Kingdom, researchers identified over 938,000 adults with an average age of 46 who had been newly prescribed antidepressants, with more than 868,000 taking SSRIs and more than 69,000 taking other antidepressants. Researchers followed study participants for an average of six years. During the study, 15,860 people had a stroke. Those participants were compared to 473,712 participants who did not have a stroke. The people who used antidepressants that increased serotonin levels the most, had a 12 percent lower risk of having an ischemic stroke than people who used antidepressants that increased serotonin levels the least. Antidepressants that increased serotonin levels the most included the SSRIs fluoxetine, paroxetine, and sertraline and the drug duloxetine, which is a selective serotonin and norepinephrine reuptake inhibitor (SNRI). Antidepressants that moderately increased serotonin levels included the SSRIs citalopram, escitalopram, fluvoxamine, and the SNRI venlafaxine. Antidepressants the increased serotonin levels the least included the antidepressants mianserin, mirtazapine, nefazodone, reboxetine, agomelatine and viloxazine, which fall into different drug classes. In the analysis assessing the risk of stroke with drugs that increase serotonin levels the most, among 2,836 people with stroke, 2,277, or 80.3 percent, took drugs that increased serotonin levels the most, whereas among 80,821 people who did not have a stroke, 66,577, or 82.4 percent, took drugs that increased serotonin levels the most. The results remained the same after researchers adjusted for factors that could affect stroke risk, such as obesity, smoking status, alcohol use and high blood pressure. 鈥淭he findings of our large study suggest that, compared with the drugs that increase serotonin the least, antidepressants that increase serotonin the most may be associated with a decrease in the risk of ischemic stroke,鈥 said Renoux. 鈥淏ut given that the decrease in risk is small, we recommend physicians choose antidepressant treatments for their patients based on effectiveness and side effects rather than the risk of stroke.鈥 A limitation of the study was that the database listed only antidepressants prescribed by general practitioners, not by specialists. However, Renoux notes that antidepressants are usually prescribed by general practitioners. The study was supported by Canadian Institutes of Health Research. Learn more about stroke at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and .