A new study from University of Illinois at Chicago researchers suggests that more than one-third of U.S. adults may be using prescription medications that have the potential to cause depression or increase the risk of suicide, and that because these medications are common and often have nothing to do with depression, patients and health care providers may be unaware of the risk. The researchers retrospectively analyzed medication use patterns of more than 26,000 adults from 2005 to 2014, which were collected as part of the National Health and Nutrition Examination Survey. They found that more than 200 commonly used prescription drugs — including hormonal birth control medications, blood pressure and heart medications, proton pump inhibitors, antacids and painkillers — have depression or suicide listed as potential side effects.

Published in the Journal of the American Medical Association, the study is the first to demonstrate that these drugs were often used concurrently and that concurrent use, called polypharmacy, was associated with a greater likelihood of experiencing depression. Approximately 15 percent of adults who simultaneously used three or more of these medications experienced depression while taking the drugs, compared with just five percent for those not using any of the drugs, seven percent for those using one medication and nine percent for those taking two drugs simultaneously. The researchers observed similar results for drugs that listed suicide as a potential side effect. These findings persisted when the researchers excluded anyone using psychotropic medications, considered an indicator of underlying depression unrelated to medication use. Co-authors on the study are Katharine Ozenberger of UIC and Columbia University’s Mark Olfson. Qato and Olfson both noted financial disclosures potentially relevant to the study.