Could common prescription medications be contributing to depression and rising suicide rates?
Over one-third of Americans take at least one prescription drug that lists depression as a potential side effect, a new study reports, and users of such drugs have higher rates of depression than those who don’t take such drugs.
Many patients are taking more than one drug that has depression as a side effect, and the study found that the risk of depression increased with each additional such drug taken at the same time.
About 200 prescription drugs can cause depression, and the list includes common medications like proton pump inhibitors (P.P.I.s) used to treat acid reflux, beta-blockers used to treat high blood pressure, birth control pills and emergency contraceptives, anticonvulsants like gabapentin, corticosteroids like prednisone and even prescription-strength ibuprofen. Some of these drugs are also sold over-the-counter in pharmacies.
For some drugs, like beta-blockers and interferon, the side effect of depression is well known, but the authors of the study were surprised at how many drugs were on the list.
“It was both surprising and worrisome to see how many medications have depression or suicidal symptoms as a side effect, given the burden of depression and suicide rates in the country,” said Dima Mazen Qato, an assistant professor and pharmacist at the University of Illinois at Chicago who was the lead author of the paper, published Tuesday in JAMA.
She acknowledged that there are still “a lot of unanswered questions,” and that the study only points to a correlation, not a cause-and-effect relationship.
“We didn’t prove that using these medications could cause someone who was otherwise healthy to develop depression or suicidal symptoms. But we see a worrisome dose-response pattern: The more of these medications that have these adverse effects that you’re taking concurrently, the higher the risk of depression,” Dr. Qato said.
The researchers used a large and nationally representative database, the National Health and Nutrition Examination Survey, to analyze the medications used by a representative sample of more than 26,000 American adults from 2005 to 2014. They researched side effects of commonly used prescription drugs, compiling a list of more than 200 medications that have depression or suicidal symptoms listed as potential side effects.
The overall use of any prescription medication that had depression as a potential adverse effect increased to 38.4 percent in 2013-14, up from 35 percent in 2005-6, the study found. The percentage of adults who were concurrently taking three or more drugs with the side effect increased to 9.5 percent in 2013-14, up from 6.9 percent in 2005-6, the report said.
The use of medications that have suicidal symptoms as potential side effects also increased, to 23.5 percent of the population in 2013-14, up from 17.3 percent in 2005.
Among patients using one drug that could cause depression as a side effect but who were not taking an antidepressant drug, 6.9 percent had depression, while the depression rate for patients taking three or more drugs with the side effect was 15.3 percent. By contrast, patients who were not taking any such drugs had a depression rate of 4.7 percent.
The researchers adjusted for other risk factors that can cause depression, including poverty, marital status, unemployment and certain medical conditions, like chronic pain, which themselves are associated with depression.
“The study is an important reminder that all medicines have risks, and most medicines have rare but serious risks — yet another reason that even commonly used medicines such as beta-blockers or proton pump inhibitors should not be used cavalierly,” said Dr. Caleb Alexander, co-director of the Center for Drug Safety and Effectiveness at Johns Hopkins Bloomberg School of Public Health, who was not involved in the study.
Dr. Philip R. Muskin, a professor of psychiatry at Columbia University Medical Center and secretary of the American Psychiatric Association, said physicians must keep these side effects in mind when prescribing medications, and ask patients about whether they have a personal or family history of depression.
But he said it is hard to say whether the increased use of drugs, and combination of drugs with side effects including depression, has had an impact on society.
“There’s been an increase in suicide, that we know,” Dr. Muskin said. “Does it correlate to the use of these medications? The honest answer is we don’t know. Could it play a role? The honest answer is yes, of course it could.”