OBJECTIVE: To investigate the long-term effects of surgically induced weight loss on the psychological functioning of morbidly obese patients. DESIGN: Comparison between preoperative and postoperative psychometric test results in a cross-sectional study. PATIENTS AND METHODS: Three psychometric tests were administered to 62 morbidly obese patients before and after surgery. RESULTS: The mean follow-up was 85.9 AE 48.1 months. Surgical treatment resulted in a mean weight loss of 45.0 AE 21.3 kg (P`0.0001). The psychometric test results before surgery demonstrated somatisation, depression, denial of emotional stress, social incompetence and an indifferent attitude towards certain aspects of interpersonal behaviour. All psychopathology, except for somatisation, disappeared after surgical treatment. Improvement of psychological functioning was determined by weight loss and not in¯uenced by the surgical procedure. The level of self-esteem before surgery predicted 15.4% of the outcome variance (P`0.05). CONCLUSION: The psychopathology before surgery is almost totally reversed after sustained, surgically induced weight loss. This suggests that the preoperative psychological disturbances are the result, rather than the cause, of morbid obesity.

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