[Changes in the pattern of substance use after bariatric surgery: report of one case].

Even though the benefits of bariatric surgery are supported by scientific evidence, its indications and contraindications must be revised to avoid its indiscriminate use. Substance use is more common in patients subjected to bariatric surgery than in the general population. After surgery, an increase in alcohol abuse has been reported. We report a 41 years old male, with morbid obesity, alcohol and cocaine use. After bariatric surgery, his alcohol tolerance significantly decreased, increasing the doses of cocaine and starting to consume it without alcohol. His high anxiety level and paranoid delusions, motivated him to seek help in a rehabilitation center where a Substance Dependence Disorder was diagnosed and received initial treatment. The cause of this adverse effect needs further research. Functional and anatomic changes in the digestive tract lead to a greater alcohol absorption and reduced alcohol dehydrogenase activity. Also neurochemical alterations may produce a displacement from compulsive use of food to compulsive use of addictive substances.