In the three years after they go under the knife, patients who have bariatric surgery to aid in weight loss are more likely than they were before the operation to attempt suicide or end up in the hospital after doing harm to themselves, new research says.

As complications of weight-loss surgery go, the hazard was rare. A Canadian study that tracked 8,815 bariatric surgery patients found that in their three post-surgical years, just 1.3% of those patients landed in the hospital following a self-harm emergency, which included intentional drug overdoses or suicide attempts by other means.

But that rate of self-injurious behavior represented a 54% increase over that seen in the same patient population during the three years before these patients had surgery.

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Published Wednesday in the journal JAMA Surgery, the new research sheds light on a grim fact about obesity: Long before an obese patient enters the OR, he or she is more likely to suffer depression and a wide range of other psychiatric ills than is the average person of normal weight. Several studies have established that bariatric surgery patients are as much as four times likelier than those who are not to attempt suicide.

In the three years before undergoing bariatric surgery, participants in the current study were already twice as likely to intentionally harm themselves as were those in the general population.

But in the three years following their surgery, these patients’ already outsized burden of mental illness took on added weight; during the post-surgical period studied, the participants were three times more likely to have a self-harm emergency than were those in the general population.

Among those most likely to experience self-harm events following surgery were low-income patients and those living in rural areas.


The new research highlights a little-recognized challenge patients face in the wake of surgery that replumbs the stomach but also drives far-reaching changes beyond the digestive system.

The authors of the current study suggest that changes in patients’ ability to metabolize alcohol in the wake of bariatric surgery might be implicated in some patients’ worsening mental health.

Following certain bariatric surgery procedures that bypass parts of the stomach, patients who drink alcohol often find their tolerance low and become inebriated quickly. Such changes, wrote the new study’s authors, may affect some patients’ risk-taking behavior and ability to suppress self-destructive impulses while under the influence.

The authors also suggested that addictive behaviors which, for some, have contributed to obesity in the first place may be displaced toward other substances, including medications, following surgery that limits stomach capacity. In the current study, 68% of the 168 self-harm emergencies noted were attributed primarily to medication overdoses.


But the study’s authors also urged further research into the possibility that altered brain chemistry wrought by the surgical replumbing of the digestive tract might contribute to depression or suicidal behavior.

The research also underscores the need for bariatric surgery practices — a specialty seeing rapid growth — to tend to the mental health of their obese patients not just before surgery, but for several years beyond. Most of the bariatric patients’ psychological crises occurred in the second and third years after surgery, a period when there’s little interaction between patients and the practices that provided their bariatric services.

Dr. John M. Morton, president of the American Society for Metabolic and Bariatric Surgery, said that the study, conducted in Canada, may not fully reflect the state of mental health screening and monitoring in the United States, where accreditation of bariatric surgery practice sets standards for the psychological screening and care of patients.

Morton said 9 in 10 bariatric procedures in the United States are conducted in accredited facilities, and he expressed confidence that patients in the U.S. were being carefully screened and prepared for the lifestyle changes needed for a successful outcome.


But Morton noted that nearly all the patients who engaged in self-harm behaviors after their surgery had a history of mental illness. That fact may help in identifying patients who will need more extensive monitoring, he said. But it also underscores that for many patients, surgery itself is often just the beginning of a longer march back to health.

“Even if you remove the burden of weight, you don’t remove the burden of disease,” said Morton, who was not involved in the study. “Some of the psychological issues might still be there.”

In a commentary also published Wednesday in JAMA Surgery, a bariatric surgeon and a psychologist experienced in the field wrote that identifying patients at risk of post-surgical psychological issues “remains an elusive goal.”

Expert opinion currently sets the standard for choosing which patients can safely get the surgery and how they should be prepared, wrote Dr. Amir Ghaferi, director of bariatric surgery for the U.S. Veterans Administration, and Michigan psychologist Carol Lindsay-Westphal. When it comes to screening, preparing and post-surgical monitoring of bariatric patients, they wrote, there’s “significant room for improvement.”


“Bariatric surgery is more than just an operation,” Ghaferi and Lindsay-Westphal wrote. “It is time we recognize and treat it as such,” they added.

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