Night eating in bipolar disorder.

Objective: Night eating syndrome (NES) involves reduced feeding during the day and evening hyperphagia sometimes accompanied by frequent nocturnal awakenings with conscious episodes of compulsive ingestion of food. Previously, NES has not been evaluated in bipolar disorder (BD). The objective of this study was to identify NES in euthymic BD patients.

Patients/methods: Eighty BD patients and 40 controls were examined using the Night Eating Questionnaire, Hamilton Rating Scale for Depression and Anxiety, Young Mania Rating Scale, Functioning Assessment Short-Test and International Physical Activity Questionnaire. Sleep quality (Pittsburgh Sleep Quality Index), daytime sleepiness (Epworth Sleepiness Scale), severity of insomnia (Insomnia Severity Index) and morning-evening preference (Morningness-Eveningness Questionnaire) were also evaluated.

Results: BD patients presented NES in 8.8% while the controls showed no NES. Patients with and without NES were not different with respect to gender, disease duration, smoking, heavy drinking, body mass index, waist-to-hip ratio and neck circumference. BD patients with NES scored higher for functioning as well as for the following specific components: occupational functioning, financial issues, interpersonal relationships and leisure time. They also had more anxiety, higher insomnia severity and worse sleep quality. Furthermore, BD patients with NES were more evening type.

Conclusion: NES occurs more frequently in BD patients than in controls. BD patients with NES present more disease-related manifestations such as more anxiety, poorer functioning and worse sleep parameters. Patients with NES were more evening type. We speculate whether changing circadian preference in these patients can reduce NES.