Why are you not able to have gastric bypass surgery if you have severe mental disorders?

Major surgery. Having gastric bypas surgery is a mjor undertaking and requires the person to have stable cardiac function, stable lung function, and yes, stable mental health. Mental health willplay a large role in the eventaul succes of gatric bypass, so it is importatn to be mentally sound to get this surgery, so a person will have the best possible outcomes.