The relationship between night eating symptoms and disordered eating attitudes via insomnia and chronotype differences.

Humans' sleep timing and the psychological construct "diurnal preference" determines their "chronotype" (i.e., morning or evening type). Diurnal preferences can affect sleep-awake rhythms and eating behaviors. Our aim in this study was to examine the relationship between night eating symptoms and disordered eating attitudes by evaluating insomnia and chronotype differences in university students. The participants, 383 university students, filled out a package of psychological tools, including the Morningness-Eveningness Questionnaire, the Insomnia Severity Index, the Night Eating Questionnaire, and the Eating Attitude Test. One way analysis of variance was used to investigate the relationship of chronotypes with scale scores, and mediation regression analysis was used to investigate the indirect effects of night eating symptoms on disordered eating attitudes. Insomnia and night eating scores of the participants varied statistically according to chronotypes, and both insomnia and night eating scores were associated with the evening type. Findings show that night eating symptoms have a direct effect on the chronotype differences and insomnia and an indirect effect on disordered eating attitudes, by increasing insomnia scores. In conclusion, night eating syndrome may represent the misalignment of food intake and may shift the circadian rhythm to delayed sleep phase, acting as a peripheral oscillator in human.

Heterogeneity of sleep quality in relation to circadian preferences and depressive symptomatology among major depressive patients.

BACKGROUND: The current study aimed at investigating the latent dimensional structure of sleep quality as indexed by the seven components of the Pittsburgh Sleep Quality Index (PSQI), as well as latent covariance structure between sleep quality, circadian preferences and depressive symptoms. METHODS: Two hundred twenty-five patients with major depressive disorder (MDD), with an average age of 29.92 ±â€¯10.49 years (aged between 17 and 63), participated in the study. The PSQI, Morningness-Eveningness Questionnaire (MEQ) and Beck Depression Inventory (BDI) were administered to participants. Four sets of latent class analyses were subsequently run to obtain optimal number of latent classes best fit to the data. RESULTS: Mixture models revealed that sleep quality is multifaceted in MDD. The data best fit to four-latent-class model: Poor Habitual Sleep Quality (PHSQ), Poor Subjective Sleep Quality (PSSQ), Intermediate Sleep Quality (ISQ), and Good Sleep Quality (GSQ). MDD patients classified into GSQ latent class (23.6%) reported the lowest depressive symptoms and were more prone to morningness diurnal preferences compared to other three homogenous sub-groups. Finally, the significant association between eveningness diurnal preferences and depressive symptomatology was significantly mediated by poor sleep quality. LIMITATION: The cross-sectional nature of the study and the lack of an objective measurement of sleep such as polysomnography recordings was the most striking limitation of the study. CONCLUSIONS: We concluded sleep quality in relation to circadian preferences and depressive symptoms has a heterogeneous nature in MDD.

The effects of individual biological rhythm differences on sleep quality, daytime sleepiness, and dissociative experiences.

Individuals who differ markedly by sleep chronotype, i.e., morning-type or evening-type also differ on a number of psychological, behavioral, and biological variables. Among several other psychological functions, dissociation may also lead to disruption and alteration of consciousness, which may facilitate dream-like experiences. Our study was aimed at an inquiry into the effects of individual biological rhythm differences on sleep quality and daytime sleepiness in conjunction with dissociative experiences. Participants were 372 undergraduate college students, completed a package of psychological instruments, including the Morningness-Eveningness Questionnaire, Dissociative Experiences Scale, Insomnia Severity Index, and Epworth Sleepiness Scale. Using logistic regression models, direct relations of pathological dissociation with sleepiness, sleep quality and circadian preferences were investigated. Poor sleep quality and sleepiness significantly contributed to the variance of dissociative symptomatology. Although there was no substantial linear association between circadian preferences and pathological dissociation, having evening-type preferences of sleep was indirectly associated with higher dissociation mediated by poor sleep quality. Poor sleep quality and daytime sleepiness seems to be significant antecedents of pathological dissociation. Sleep chronotype preferences underlie this relational pattern that chronobiological characteristics seem to influence indirectly on dissociative tendency via sleep quality.