Clinical and Polysomnographic Features of Sleep-related Eating Disorder

Background: Sleep-related eating disorder is a recently described clinical syndrome that combines characteristics of both eating and sleep disorders. Nocturnal partial arousals are followed by rapid ingestion of food and subsequent poor memory for the episode. Only two case series examining this disorder have been published, and both are from the same sleep disorders center in a general hospital.

Method: The author describes 23 consecutive cases of sleep-related eating disorder that presented to the Sleep Disorders Center at McLean Hospital. All patients were administered at a standardized clinical sleep disorders evaluation followed by a semistructured interview to elicit information regarding characteristics of sleep-related eating disorder. Polysomnographic evaluation was performed on all patients with clinical histories of sleep-related eating disorder.

Results: Eighty-three percent (N = 19) of the 23 patients were female. For most of the patients, the disorder had begun in adolescence (mean +/- SD = 21.6 +/- 10.9 years) and had been chronic, with a mean duration of 15.8 +/- 11.2 years. Nearly all patients reported eating on a nightly basis (1-6 times per night), and all episodes followed a period of sleep. All patients described their eating as "out of control," and two thirds stated that they "binged" during the night. Over 90% (21/23) reported their state at the time of nocturnal eating as "half-awake, half-asleep" or "asleep", and over 90% reported "consistent" or "occasional" amnesia for the event. Nearly half (11/23) of the sample were given a polysomnographic diagnosis of somnambulism. Thirty-five percent (8/23) had a lifetime eating disorder diagnosis.

Conclusion: Sleep-related eating disorder appears to be a relatively homogeneous syndrome combining features of somnambulism and daytime eating disorders. However, no current nosology accurately characterizes these patients. Physicians should be aware of the existence of the disorder and the value of referring patients with sleep-related eating disorder to a sleep disorders center.