The Role of Psychological Factors in Bariatric Surgery for Morbid Obesity: Identification of Psychological Predictors of Success

Abstract

This paper deals with two important questions in the outcome of surgical treatment for morbid obesity. First, what is the impact of bariatric surgery on psychological functioning or quality of life? Second, and perhaps more important, can pre-surgical factors be identified that predict the outcome of surgery? These questions are answered by a systematic review of the current literature in this area. Throughout this paper the need for methodological rigour is stressed, and conclusions are based only on empirically sound findings. It is concluded that surgery is generally associated with improved psychological functioning and quantity of life for most individuals. While a significant minority of morbidly obese individuals do not respond positively to surgery, there is no evidence to support the theory that obesity is a psychological defense mechanism, and therefore that bariatric surgery will produce widespread psychological problems. On a less positive note, while some studies identify pre-surgery psychological factors that predict weight loss following surgery, there has been no attempt to systematically replicate findings across studies, and no consistent findings have emerged from the literature. Due to the fact that the predictor variables examined have not been selected on theoretical grounds, the interpretation of isolated findings is difficult. On the basis of this review, however, distress over obesity appears to be a potentially important psychological predictor of the success of surgery. Unfortunately, there currently is no measure to specifically measure distress over obesity. What is needed at this time is a theoretically derived approach to the development of a scale to assess distress over obesity.