Wernicke's encephalopathy after gastric bypass that masqueraded as acute psychosis: a case report.

Wernicke's encephalopathy was originally described more than a decade ago. It has been reported after many causes of malnutrition. This case presents a patient with thiamine deficiency after gastric bypass, although unusual in itself, further complicating the case was the initial diagnosis of acute psychosis that was scheduled for electroconvulsive therapy. After recognition and intervention, the patient was successfully treated with thiamine replacement and parenteral nutrition.