Risk of Suicide Is Increased After Bariatric Surgery

A call for closer postsurgical monitoring.

When bariatric surgery arrived on the scene as the treatment of choice for persons with a body mass index (BMI) of 40 kg/m² or greater, it seemed to be a real boon for patients who could not lose weight with standard diets or other approaches. Annual rates of bariatric surgery have increased markedly over the past decade; for example, by 400% from 1998 to 2002. Now, however, a serious downside has emerged: an increased risk of suicide after patients recover.

Hilary A. Tindle, MD, MPH, and co-workers at the University of Pittsburgh and the University of California, Davis, recently found a substantial excess of suicides among all patients who had bariatric surgery in Pennsylvania during a 10-year period (Am J Med 2019; 123:1036). They uncovered this trend after examining post-bariatric surgery suicides by time since operation, as well as by sex, age, and suicide death rates, and then comparing this with U.S. suicide rates.

Dr. Tindle and colleagues examined medical data after bariatric operations performed on Pennsylvania residents between January 1, 1995 and December 31, 2004, using the Pennsylvania Health Care Cost and Containment Council database. Matching mortality data were obtained from the Division of Vital Records of the Pennsylvania State Health Department. The researchers found reports of 31 suicides from 16,683 operations, for an overall rate of 6.6 suicides per 10,000 population (13.7 per 10,000 among men and 5.2 per 10,000 among women). About 30% of the suicides occurred within the first 2 years after bariatric surgery, and almost 70% occurred within 3 years after surgery. In comparison, age- and sex-related suicide rates in the U.S. among people 35 to 64 years of age were 2.4 per 10,000 for men and 0.7 per 10,000 for women.

Among the Pennsylvania patients, mean time to death was about 3 years after bariatric surgery, and 10% of the suicides occurred in the first year post-surgery, 29% within the first 2 years and 68% within 3 years. Men had higher rates of suicide in each age category except those 24 years of age or younger, and the rate of suicide among men was more than twice that of women. Suicide occurred most commonly among men from 45 to 54 years of age (21.7 per 10,000) while women under 35 had the highest rates (about 14.0% per 10,000). These rates are all substantially higher than those for the general age- and sex-matched U.S. population over the same time period. Four main modes were used for suicides: drug overdose (16 cases), gunshot wounds (9 cases), carbon monoxide poisoning (4 cases), and hanging (2 cases).

Finding the cause behind the statistics

Although others have reported an excess of suicide deaths after bariatric surgery, most of these cases occurred more than a year after surgery and the small absolute number of cases has limited the ability to define statistical differences between those who had surgery and control patients (N Engl J Med 2007; 357:753).

The reasons for the increased risk are still unknown, but Dr. Tindal and colleagues have uncovered some possibilities. For example, presurgical psychopathology might contribute to postsurgical outcomes, and some studies have shown that a lifetime history of mood or anxiety disorders is associated with a smaller decrease in BMI during the first 6 months after surgery. The role of weight change may also be important in the risk. Sansone and colleagues reported that 10% of bariatric surgery candidates had a history of prior suicide attempts, a major risk for suicide mortality (J Psychosom Res 2008; 65:441). It is possible that patients in the current study who were initially successful with weight loss eventually regained the weight and became depressed about it. Also, the authors pointed out that most suicides occurred during the time when clinical follow-up and monitoring was waning.

Some study limitations

The authors point out that despite the strengths of their study, including the fact that they were able to report the causes of death for all individuals who underwent bariatric surgery in Pennsylvania for the time period, they did not have information on the frequency of suicides among different bariatric surgery programs in Pennsylvania—that is, they were unable to learn if characteristics of a program, such as the number of patients, type of surgery, and extent of medical and psychological follow-up, might play a role. They also could not sort out factors that might have contributed to increased risk, including mental illness, distress or depression, from the effects of bariatric surgery itself.

Finally, the authors underscore the importance of a systematic, long-term monitoring program to follow patients who have had bariatric surgery, which might act as a helpful deterrent.