The results of several studies on sleep EEG and dreams in patients with eating disorders are presented and compared with the data obtained in patients with a major depression. The sleep pattern, which is characteristic of depression, could not be found in the eating disorder group. Regarding the cholinergic REM induction test, the depressives displayed a pronounced shortening of REM sleep latency. However, this biological marker, indicating a cholinergic hyperactivity in depression, could not be observed in patients with eating disorders. The content analysis of laboratory-recorded dreams yielded several differences between depression and eating disorders and also, more subtle, between anorexia and bulimia.