About 11% of Americans over age 12 take an antidepressant, making the drugs the most widely used medication in the United States. And with more than 51 million in-patient surgeries performed annually in the United States, a substantial overlap between the two patient populations -- those on antidepressants and those facing surgery -- is a certainty.
What's not so certain is how antidepressants -- and specifically the most widely used class of depression medication, known as selective serotonin reuptake inhibitors, or SSRIs -- may affect the outcomes of surgical patients. Two new studies out this week explored this question, with findings that are, well, a little depressing.
Despite one study's evidence of some benefits for heart patients undergoing artery-clearing procedures, a second study found that among patients undergoing all types of surgery, taking SSRIs at the time of surgery was linked to slightly higher rates of death and complications, particularly bleeding, than not taking an SSRI.
The two studies focused on different kinds of patients and on two different issues raised by antidepressants.
The first study, published Tuesday in JAMA Internal Medicine, investigated whether a recognized side effect of SSRIs -- that they suppress aggregation of red blood cells, or platelets -- might make it unhelpful for patients to be taking them about the time that they are undergoing surgery.
Looking backward at more than 500,000 patients across the country who got major surgery between the beginning of 2006 and the end of 2008, the authors of the study picked up a tentative signal that patients who take SSRIs about the time of major surgery are at slightly higher risk of dying in the hospital, of bleeding that requires transfusions, and of hospital readmission within a month of their discharge.
But the authors acknowledge that it may not be the antidepressants that affected outcomes, but the kinds of patients who are most likely to be taking them: People on antidepressants were more likely to be obese and more likely to have chronic pulmonary obstructive disorder or hypothyroidism than those who do not take the medication. And they were more likely than those not taking the medication to be depressed, which can make a patient less likely to take care of herself or follow doctors' orders following surgery.
Gleaning whether it's the antidepressants or the patients who take them that matter more will take additional -- and more expensive -- research to determine, said the authors, who came from UC San Francisco, University of Massachusetts, Tufts University and Baystate Medical Center in Massachusetts.
The second study, published Wednesday in the Annals of Thoracic Surgery, acknowledged the long-observed links between depression and heart disease -- first, that patients with a history of depression are far more likely than those without to develop heart disease; and second, that patients who develop depression, say, after a heart attack or an artery-clearing procedure are more likely to die than those who are not depressed.
Those links prompted the American College of Cardiology and the American Heart Assn. several years ago to recommend that all heart disease patients be screened for depression. But cardiologists have remained skeptical of that advice, since they do not know whether such patients, when treated with, say, SSRIs, will do better or worse.
The latest research appears to fly in the face of the JAMA Internal Medicine study: Compared with subjects who got a placebo, study participants who started taking the SSRI escitalopram (better known by its commercial name Lexapro) from two to three weeks before surgery until six months after were not more likely to experience excessive bleeding or death in the year following their artery-clearing surgery.
But neither were those taking an antidepressant less likely to die or have a dangerous bleeding episode than those on a placebo.
The French authors of the study did find that CABG patients who went on an SSRI before their procedure and stayed on it for six months had less pain and were less likely to be depressed in the six months following their surgery. That was particularly true for subjects who went into the procedure with signs of clinical depression.
Dr. Marc Penn, who was not associated with either study, said the findings of SSRIs' benefit for CABG patients was some of the first evidence to offer such rigorous assurances. Penn suggested that by improving moods in patients with a propensity to depression, SSRI benefits might be even more evident after a year, when the effects of such patients' sustained changes in diet and exercise would become more evident.
"I take away from this that patients who are prone to depression or melancholy going into bypass surgery are going to feel better in the post-op state if they're pretreated for their depression," said Penn, chief of cardiovascular research at Summa Health Systems in Akron, Ohio. "We know people with coronary disease who take care of themselves will do better than people who don't."
And those who are at risk of becoming depressed when a major life event -- a heart disease diagnosis -- happens stand a better chance of taking care of themselves if that prospect is nipped in the bud, he said.