Bariatric surgery is the most effective weight-loss option for people who are severely obese. However, the surgery involves substantial risks and requires a lifelong commitment to behavioral change. People eligible for the surgery often have a history of mental health problems or eating disorders. Therefore, patients must be prepared mentally as well as physically before surgery, reports the January 2008 issue of the Harvard Mental Health Letter.

The psychological aspects of bariatric surgery are less well understood than the physical risks and benefits. Although the surgery is generally associated with improved mental health and quality of life, postsurgical psychological and behavioral changes are less predictable than physical changes.

The Harvard Mental Health Letter notes that mood disorders such as depression and anxiety affect many people who are eligible for bariatric surgery. The weight loss following surgery generally improves mood, at least initially. In studies, depression and anxiety scores were reduced significantly one year after surgery, but tended to be higher two and four years later. And some research has found higher-than-expected rates of suicide among surgery patients.

Eating disorders, such as binge eating, also affect many people considering bariatric surgery. And a highly controversial theory—as yet unproven—is that bariatric surgery may cause some people to lose weight but then “transfer” their food addiction to some other harmful addiction. Surgery may change the rate at which alcohol is absorbed, which may increase the risk of dependence in people who are vulnerable to becoming addicted. All of these factors underscore the need for mental health treatment before and after surgery, says the Harvard Mental Health Letter.