Many patients undergoing radical gastric bypass surgery suffer from depression or anxiety disorders, according to researchers at the Center for Weight Reduction at Montefiore Medical Center in New York.

These patients should first be evaluated by a mental health worker, according to their report in the journal Obesity Surgery.

"There is a high degree of psychopathology in this population, which could influence their ability to make informed consent and/or their reaction to the surgery and subsequent weight loss," wrote the authors.

In their study of 115 surgical candidates, researchers found that 70 percent had a current or past mental disorder. Anxiety disorders were prevalent in 17 percent of the patients.

"These are significant findings," said Dr. Elliot Goodman, chief of Bariatric Surgery and co-author of the study. "We tend to measure success in terms of weight loss alone. We have neglected to measure outcome in terms of other medical and psychological complications, satisfaction with surgery, nutritional intake, exercise level, measure of self-esteem, interpersonal functioning and work functioning. More studies are needed to further clarify which psychological factors play a role in these outcome variables."

Other sources: Montefiore Medical Center