Adverse psychosocial consequences of extreme obesity and the effects of surgically induced weight loss

Adverse psychosocial consequences of extreme obesity 

Mood. Extreme obesity is associated with significantly increased mortality, principally from cardiovascular disease, type 2 diabetes mellitus, and several cancers [1], [2]. Although less well known, this condition also is associated with a marked increase in the risk of depression [3], [4]. A recent population study found that persons with a body mass index (BMI) ≥ 40 kg/m2 were five times more likely than individuals of average weight to have experienced an episode of major depression in the past year [4]. Among persons who seek bariatric surgery, approximately 50% have a history of depression or other affective disturbance [5], [6], [7]. Patients frequently seek weight reduction to alleviate their emotional distress.

Eating disorders. Eating disorders also are common in bariatric surgery patients. Approximately 25% suffer from binge eating disorder (BED), which is characterized by the consumption of an objectively large amount of food in a brief period (< 2 hours), during which the individual experiences subjective loss of control [6], [7], [8], [9], [10]. Binge episodes cause significant emotional distress. But they are not followed by purging (eg, vomiting), which distinguishes BED from bulimia nervosa. The rate of BED in the general population is only 2% [11].

Quality of life. If not associated with frank psychiatric illness, extreme obesity is almost universally associated with decreased health-related quality of life (HRQL). HRQL refers to the burden of suffering and the limitations in vocational and social functioning associated with illness [12]. Numerous population and clinical studies have shown that compared with average weight individuals, extremely obese persons report significantly greater bodily pain, decreased vitality, and significant impairments in physical functioning, work, and social interactions [13], [14], [15].

But even quality of life scales cannot adequately measure the adverse emotional effects of the prejudice and discrimination to which extremely obese individuals are subjected daily [16]. Disparagement of obese individuals has been described as the “last socially acceptable form of prejudice” [17]. Overweight individuals are routinely labeled, even by health care professionals, as “weak-willed, awkward, ugly, and sloppy” [18]. Sadly, such ridicule engenders negative body image and feelings of inferiority in many obese individuals [6], [7]. Studies also have documented that obesity is associated with adverse economic and social consequences, particularly in women [19], [20]. For many, extreme obesity carries an enormous emotional burden that far exceeds that associated with physical illness.

Improved psychosocial functioning after bariatric surgery 

Quality of the evidence. Research on the psychosocial consequences of bariatric surgery has increased substantially over the past decade and has shown that weight loss is associated with lasting improvements in mood, eating disorders, and quality of life [5], [6], [7]. It is too early to tell whether one form of surgery, such as gastric bypass or laparoscopic adjustable banding, is superior to another in improving symptoms of depression or binge eating. Evidence suggests that long-term improvements are associated with the magnitude and stability of weight loss. Similarly, there are not adequate data to state definitively whether psychosocial status improves comparably in older and younger patients, although clinical impressions suggest no age-related differences. Finally, randomized controlled trials, which include a no-treatment condition, have not been conducted in this area. However, the Swedish Obese Subjects (SOS) study included a carefully matched control group and revealed significantly greater improvements in psychosocial status in persons who lost weight with bariatric surgery [21].

The next sections briefly review changes in depression, eating disorders, and quality of life. The examination relies heavily on prior reviews [5], [6], [7] and includes the strongest data available. This includes the SOS study, as well as prospective, noncontrolled investigations that measure psychosocial status at regular intervals using structured clinical interviews or well-validated questionnaires.

Mood. In the SOS study, depression scores fell significantly more at 1 year in surgically treated patients than in control patients (40% vs 10% reduction, respectively). Similar improvements were observed in anxiety. At both 2- and 4-year follow-up evaluations, larger weight losses were associated with significantly greater improvements in both depression and anxiety [21], [22]. Mean weight loss at 2 years, which was induced primarily by vertical banded gastroplasty, was approximately 23% of initial weight.

Dixon et al [23] recently reported similar improvements in depression after a 20% reduction in initial weight achieved with laparoscopic adjustable banding. The mean presurgical score of 17.7 on the Beck Depression Inventory indicated moderate symptoms of depression. One year after surgery, this value fell to 7.8 and remained at 9.0 at a 3-year follow-up. These values indicate minimal symptoms of depression. Although weight loss achieved with diet and exercise is also associated with improvements in depression, these benefits are not maintained. Depression scores return to baseline levels as patients regain their lost weight, an all-too-common occurrence with behavioral interventions [24]. Numerous other investigations have demonstrated lasting reductions in both depression (and weight) with bariatric surgery [5], [6], [7].

Eating disorders. Several studies have shown that bariatric surgery is associated with nearly complete remission of BED [25], [26], [27], [28]. The small gastric pouch simply prevents patients from consuming an objectively large amount of food. In addition, surgery is associated with reductions in both hunger and disinhibition of appetite (ie, urges to overeat), as measured by the Eating Inventory [21], [29]. Although most investigations were uncontrolled, the SOS study found significantly greater improvements in surgically treated patients than in control patients over 2 years of observation [21].

Favorable changes in BED and appetite also have been reported in obese individuals treated by diet and exercise [30]. Once again, however, these improvements decay over time as patients regain lost body weight. A minority of surgically treated patients report feeling loss of control over their eating 2 or more years after surgery [31]. However, they still would appear to enjoy substantially greater long-term improvements in eating habits and appetite control than persons who receive traditional diet and exercise interventions.

Quality of life. Weight loss after bariatric surgery is associated with dramatic improvements in HRQL, as measured by the Short-Form Health Survey (SF-36) [32]. Nguyen et al [33], for example, found that patients who underwent gastric bypass, performed either laparoscopically or using an open technique, reported marked reductions in bodily pain, greater vitality, and improved general health and physical functioning. The patients’ scores were approximately 50% below national norms before surgery, but rose to these values only 3 months after surgery. In the first month, HRQL improved more rapidly in patients who underwent laparoscopic (rather than open) procedures, but the two groups showed equivalent improvements at 3 months. Other investigators have reported similar changes in HRQL [5], [6], [7] and observed that greater weight loss is associated with greater improvements [34].

Surgically treated patients in the SOS study also reported significantly greater improvements in HRQL than did control individuals [21]. Many improvements concerned patients’ greater comfort in social interactions in which their weight had previously inhibited them. Thus, after weight loss, surgically treated patients were significantly less troubled by events such as going to the movies, shopping for clothes, or being seen in a bathing suit. Even more eloquent testimony of improved HRQL after bariatric surgery is provided by patients studied by Rand and Macgregor [35]. Persons who had lost 45 kg or more and kept it off for 3 years or more reported that they would rather be normal weight, yet have a major handicap (eg, blindness, leg amputation, severe acne), than be morbidly obese again.

Summary 

This review has shown that extreme obesity is associated with significant psychiatric morbidity and impaired HRQL that in many cases imposes a greater burden of suffering than the physical complications of obesity. Research on this topic is in its infancy but is improving rapidly. Initial findings leave little doubt that the sustained weight loss resulting from bariatric surgery is associated with marked and sustained improvements in psychiatric status and HRQL.