Night eating behavior as a full mediator in the relationship between impulsivity and sleep quality in bipolar disorder

The aim of this study is to investigate the associations between impulsivity, night eating symptoms (NES), and sleep quality in patients with BD in remission, while also investigating confounding effects of chronotype differences, demographic/clinical variables, and the presence of metabolic syndrome (MetS). One hundred and twelve euthymic patients with bipolar disorder (BD) type 1 were enrolled in this cross-sectional study. In addition to sociodemographic/clinical data, sleep quality, impulsivity, night eating syndrome and chronotype were evaluated using the Pittsburgh Sleep Quality Index (PSQI), Barratt Impulsiveness Scale-11 Short Form, Night Eating Questionnaire, and The Munich Chronotype Questionnaire. The MetS was examined according to the criteria of the International Diabetes Federation. Our study showed a positive correlation between poor sleep quality, impulsivity, and NES. When the sample was divided into two groups based on sleep quality, as scored according to the PSQI, 58% of the patients had poor sleep quality. Those with poor sleep quality exhibited higher levels of impulsivity and severe NES than those with good sleep quality. The mediation regression model indicated that NES fully mediates the relationship between impulsivity and sleep quality, after controlling for confounding factors, including certain sociodemographic and clinical variables, antipsychotic dose (mg/day), the presence of MetS, and chronotype differences. Evaluating night eating behaviors and impulsivity associated with poor sleep quality during remission in BD patients may be crucial for developing effective intervention strategies to prevent relapses and improve the prognosis of the disease.