Sixty patients who experienced postoperative delirium were compared with a group of 57 control patients, matched on the basis of type of surgery, age, and sex, who did not experience delirium. Significant differences were found between the two groups in categories of organic, social-environmental, and emotional disorders. These findings support the concept that delirium, at least when it occurs after operation, is a multidetermined syndrome and is not solely the product of organic brain disease.Abstract Teaser