By Christina Frangou
Orlando, Fla.—Depression and anxiety do not interfere with the amount of weight patients lose after bariatric surgery, according to two studies presented at the 2011 annual meeting of the American Society for Metabolic and Bariatric Surgery.
But the research does show that the relationship between depression and bariatric surgery is complex. Some patients come off antidepressant medication after surgery, whereas others started on it or required increases in dosage postsurgery.
Moreover, one of the studies found that depression is associated with increased rates of hospital readmission and more frequent returns to the operating room (OR), a finding that could color how surgeons counsel patients prior to surgery, said investigators.
“That’s certainly something to consider when you are counseling patients about their surgery,” said lead author Anthony Galitsky, MD, who worked on the study during his fellowship in general surgery at the Lahey Clinic in Burlington, Mass.
In the first study, University of Michigan researchers examined data from 25,469 patients across 29 hospitals in the Michigan Bariatric Surgery Collaborative, a consortium of the state’s hospitals and surgeons that maintains a prospective registry of bariatric surgery patients. Between 2006 and 2010, researchers found 11,687 bariatric patients, or 46%, were treated for at least one psychiatric disorder, with depression and anxiety among the most common at 41% and 15%, respectively. Follow-up studies were conducted each year for three years postsurgery.
Whether depressed or not, patients with morbid obesity lost about 60% of their excess weight within one year and reported an average 30% improvement in quality of life. Patients with clinically diagnosed depression, however, had a higher rate of minor complications (4% vs. 3.3%) than nondepressed patients.
Among patients with depression, use of antidepressant medication dropped by about 20%, from 72% to 60%, one year after surgery and remained at that level three years after surgery.
“This study showed that psychiatric illness is very common among bariatric surgery patients but patients suffering from depression can experience health outcomes and quality-of-life improvements comparable to nondepressed patients,” said lead study author Jonathan F. Finks, MD, assistant professor of surgery at the University of Michigan, Ann Arbor.
“We need to consider and evaluate psychiatric illness before surgery, but I do not think these tests should be used as a litmus test as to who should qualify for surgery.”
In the second smaller study, patients with depression again lost comparable amounts of weight to their nondepressed counterparts.
But in this study, there were some differences in the findings compared with Dr. Finks’ study. Investigators found no improvement in postoperative medication use, as well as clinically important increases in the number of hospital readmissions and returns to the OR among patients with preoperative depression.
About 13% of patients with depression were readmitted in the first three months after surgery, 2.5 times more than among those without depression (P<0.0060). They also underwent more reoperations, with 9.4% returning the OR compared with only 3.5% for other patients (P=0.0122), and they had more contrast upper gastrointestinal series performed in the first year. One out of two underwent these postoperative tests, compared with 37.8% of patients without preoperative depression (P<0.0087).
“That will be very important for surgeons to consider in preparing people for bariatric surgery, cost and follow-up care of people with depression after bariatric surgery,” said senior author Dmitry Nepomnayshy, MD, fellowship director in bariatric surgery and assistant professor of surgery at Tufts Medical School, Boston.
If the results are confirmed with future studies, it may be that depression is associated with more postoperative complications than diabetes or hypertension, said Daniel Cottam, MD, bariatric surgeon at Surgical Weight Loss Center of Utah, Salt Lake City.
“Depression could be the one disease process that portends higher postoperative costs,” he said, adding that his own experience suggests this is true. “My depressive patients do use more resources than my nondepressive patients.”
However, in the first study, there were no significant differences in major complications, reoperations or readmissions among patients with depression.
The differences in the two studies may arise from variations in data gathering, said Dr. Nepomnayshy. The Lahey study is based on a retrospective review of electronic medical records with current medication, and the national study stems from data report into a large database so some of the data may be incomplete. However, the Lahey study is smaller and may be underpowered, “although that is unlikely,” said Dr. Nepomnayshy.
Dr. Nepomnayshy and colleagues reviewed the medical records of patients who underwent Roux-en-Y gastric bypass at the Lahey Clinic between 2006 and 2009.
Of 467 patients who had bariatric surgery, 186 patients (40%), were taking antidepressant medication before their surgery. One year later, depression medication use was almost unchanged, with 182 (39%) patients talking antidepressants, including 23 who started postsurgery.
“Both these studies show how difficult this population is to treat from a psychological perspective,” said Dr. Cottam.