While people with NES are fully conscious and aware of their eating episode as it occurs, those with SRED are partially or fully unconscious while eating, in a similar way to people who sleepwalk.3 NES also differs from BED–, another overlapping and sometimes co-occurring disorder that was granted formal diagnostic status in the DSM-5. People with NES do not necessarily eat large amounts of food during their night-eating episodes, and recent findings suggest a distinction pertaining to emotional functioning: While previous research has linked BED with high levels of alexithymia — the inability to identify, recognize and describe one’s emotions, a study published in Eating Behaviors in April4 found no such association among NES patients.
A 2012 study,5 however, linked NES with high levels of emotional and external eating — eating in response to environmental cues versus internal appetite-related cues, as observed in BED patients.6 “I think what underlies the emotional and external eating scores is stress,” said study co-author Laurence J. Nolan, PhD, a professor in the Department of Psychology at Wagner College in Staten Island, N.Y. “Emotional eating as measured in this study is eating associated with negative emotion which is, in turn, associated with stress.”
Studies suggest that NES is caused by a convergence of stress and genetic predisposition. “According to the biobehavioral model of NES, an inherited trait or predisposition for NES, when combined with stress, reduces the amount of serotonin in the brain, thereby dysregulating circadian rhythms and decreasing satiety,” Jillon Vander Wal, PhD, a professor and licensed psychologist at Saint Louis University in St. Louis, Missouri, told Psychiatry Advisor. “This model suggests that we can intervene in several ways to reduce the symptoms of this disorder.”
One way is to reduce stress, which according to the biobehavioral model, should help prevent the serotonin dips that cause NES symptoms. In a study1 this year by Vander Wal and colleagues, participants who learned progressive muscle relaxation (PMR) had a subsequent reduction in night eating of approximately 31%, as well as decreased measures of depression and perceived stress. A second path of intervention is to increase serotonin levels with the use of medications like sertraline and escitalopram.