Bimodal diurnal preference in undergraduate students is associated with negative health and sleep outcomes

ABSTRACT

The bimodal preference is a fourth diurnal preference proposed by re-scoring the Morningness-Eveningness Questionnaire. The present work aimed to describe the prevalence of the bimodal preference in a sample of undergraduate students and to characterize the bimodal type in terms of their health and sleep-related outcomes. A web-based cross-sectional study conducted between September 2018 and March 2021 (convenience sampling method). The sample was composed of undergraduate students who completed an electronic form that included the Morningness and Eveningness Questionnaire, the Pittsburgh Sleep Quality Index, the Self-Compassion Scale, the Epworth Sleepiness Scale, the Hospital Anxiety and Depression Scale, and the World Health Organization Subjective Well-Being Index. The final sample consisted of 615 students (82% female, mean age: 23.4 ± 6.5 years), of whom 108 (18%) had positive bimodality indexes. Bimodal subjects comprised 48 students, 8% of the total sample. Bimodal subjects had poorer subjective sleep quality, more daytime sleepiness, lower subjective well-being, greater anxiety and depression symptoms, and lower self-compassion than morning and/or intermediate types; they did not differ from evening types. The description of bimodal diurnal preference in this population may be of interest for the design of academic policies more in line with the circadian reality of students.

KEYWORDS:

• Chronotype
• morningness eveningness
• psychological well-being
• chronobiology phenomena
• sleep
• sleepiness
• mental health

Acknowledgments

We would like to thank the volunteers who made this work possible.

Disclosure statement

JRSV is a service provider for SleepUp^TM (a Brazilian online CBTi company) but declares that her position had no relationship to the aims, preparation, or execution of this study. Other authors have no disclosures.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2024.2349684

Additional information

Funding

This work was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (process number 2018/18889-8); the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (scholarship for JRSV; fellowship for FML, ST and VDA); the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); the Associação Fundo de Incentivo à Pesquisa (AFIP).