Moderating effect of shift work on sleep and depression in individuals at high risk of bipolar disorder

• Published in: Journal of affective disorders Vol. 359; pp. 206 - 214
• Main Authors: Yeo, Hyewon, Lee, Jooyoung, Jeon, Sehyun, Hwang, Yunjee, Kim, Jichul, Lee, Somi, Kim, Seog Ju
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.08.2024
• Subjects: Adult; Bipolar disorder; Bipolar Disorder - psychology; Cross-Sectional Studies; Daytime sleepiness; Depression; Depression - epidemiology; Depression - psychology; Female; Humans; Insomnia; Male; Middle Aged; Risk Factors; Shift work; Shift Work Schedule - adverse effects; Sleep; Sleep Disorders, Circadian Rhythm - epidemiology; Sleep Disorders, Circadian Rhythm - psychology; Sleep disturbance; Sleep Initiation and Maintenance Disorders - epidemiology; Sleep Initiation and Maintenance Disorders - psychology; Sleep Quality; Sleep Wake Disorders - epidemiology; Sleep Wake Disorders - psychology; Surveys and Questionnaires; Work Schedule Tolerance; Young Adult; Sleep disturbance; Bipolar disorder; Depression; Daytime sleepiness; Insomnia; Shift work
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2024.05.090

Social Zeitgeber Theory posits that disruptions in social rhythms can increase susceptibility to bipolar disorder (BD). Shift work (SW) is one of the external factors that cause instability in social rhythms and the sleep-wake cycle. This study evaluated the moderating influences of SW on the risks of BD and sleep-related parameters and depressive symptoms. Furthermore, we evaluated the specific work schedules including daytime, nighttime, and regular and irregular rotating SW. An online survey was administered to 6665 participants, with 3379 (50.7 %) classified as individuals with high scores of Mood Disorder Questionnaire (MDQ). The survey included the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Scale (ISI), Epworth Sleepiness Scale (ESS), and Center for Epidemiologic Studies Depression Scale (CES-D). A multivariate regression model revealed significant interactive effects of MDQ positivity and SW on PSQI, ISI, and CES-D scores, but not ESS scores. In a secondary analysis of the high MDQ screen group, daytime workers had lower scores in sleep disturbances and depressive symptoms compared to those engaged in other forms of SW. Online surveys were accessible voluntarily, leading to potential selection bias. Cross-sectional data identified associations, not causal relationships. Only a self-reported questionnaire was used. Our findings emphasize the advantages of a daytime work schedule for individuals at high risk of BD. In accordance with the principles of social rhythm interpersonal therapy, sleep interventions for individuals at high risk of BD should include the maintenance of a consistent daytime schedule. •High-risk bipolar disorder (BD) people had more sleep problems and depressive symptoms than low-risk BD people.•Shift work (SW) and bipolarity significantly impacted sleep disturbances, insomnia, and depressive symptoms.•SW and bipolarity had no significant interaction effect on excessive daytime sleepiness.•All forms of SW were linked to higher sleep problems and depressive symptoms than daytime work in high-risk BD people.