Q & A: Could This Be a Case of Night Eating Syndrome?

Q: A patient I’ve been treating for a mood and anxiety disorder who takes divalproex and lorazepam informed me that his wife has been concerned by his increasingly strange nocturnal behavior. For several months his wife tells him he’s had frequent episodes of getting out of bed in the middle of the night and acting “out of it,” during which time he basically sleep-walks to the kitchen and eats large amounts of food before returning to bed. This has happened often enough so that he’s been gaining weight. Is this pattern what is meant by the “night eating syndrome”? Do you have any advice as to how to treat this problem? (C.G., Odessa, TX)

A: Several eating disorder syndromes have been described in association with disturbances in sleep and in circadian patterns. These disorders are usually diagnosed under the DSM-IV EDNOS category (eating disorders not otherwise specified). The eating disorders workgroup for DSM-V is considering whether or not to propose that Night Eating Syndrome (NES) be separately listed in an appendix as a “condition that may be the focus of clinical attention,” and therefore a condition also worthy of further investigation. (http://www.dsm5.org/ProposedRevisions/Pages/proposedrevision.aspx?rid=26). That said, what you’re describing is less typical of NES per se than of another distinct syndrome in which eating and sleep disturbances have been linked, i.e., sleep-related eating disorder (SRED).

NES and SRED are quite different. NES could be considered an abnormality in the circadian rhythm of meal timing with a normal circadian timing of sleep onset, i.e., with individuals eating a substantial part of their daily intake in the evening after their usual dinnertime, and before they go to sleep. Conversely, the feeding behavior in SRED is characterized by recurrent episodes of eating after an arousal from nighttime sleep, with or without amnesia. In addition to eating other foods, in SRED episodes patients will sometimes eat foods that are ordinarily unpalatable, for example, raw flour and raw bacon.

Both conditions are often relentless and chronic. SRED is frequently associated with other sleep disorders, in particular parasomnias, such as sleep-walking. Case reports have linked some cases of SRED to the use of certain psychotropic medications, including tricyclic antidepressants, anticholinergics, lithium, triazolam, olanzapine, risperidone, and zolpidem. I’ve personally seen cases associated with use of thioridazine, lorazepam and divalproex. Early studies have suggested that the antiseizure medication topiramate may be an effective treatment for SRED (Sleep Medicine Reviews. 2009; 13, 23e34).

—J.Y.