Researchers in Canada included nearly 9,000 adults in Ontario who had bariatric surgery, most commonly Roux-en-Y gastric bypass, between 2006 and 2011. They looked at how many times those patients went to the emergency room for trying to harm themselves, such as by drug overdose or physical injury, in the three years before and after surgery.
The researchers found that, even before surgery, people in the study were about twice as likely to hurt themselves as the general population. There were 2.33 incidents out of 1,000 patients each year before surgery in the study group.
However, the risk increased even more after surgery; there were 3.63 incidents for every 1,000 people each year during this period. Many of the cases overall had to be rushed to the hospital and involved a hospital stay.
People with obesity, such as those in this study, have higher rates of mental health problems, such depression and substance misuse, although the reasons are not clear. Experts have suggested that increases in stress hormones and inflammation associated with obesity could contribute to depression.
This doesn't surprise me to be honest. If the patients were obese in part due to "eating their feelings", I could see them turning to other methods to cope with unresolved emotional issues.