Is there an association between the lunar phases and hospital admission for different episode types in bipolar disorder? A retrospective study in northern China

ABSTRACT

The effects of the moon on mental activities remain contentious. Few studies have investigated associations between lunar phases and different types of bipolar disorder (BD) episodes. In the current study, 7,452 patients with BD from three hospitals were enrolled. Patients were divided into two groups on the basis of episode types, and the effects of lunar phase were examined for each type. The cosinor analysis revealed moon-related rhythmicity in admissions for BD in a period of 14.75 days. There were fewer admissions around the new moon and the full moon. There was no significant difference between different groups in acrophase. There was possibly a temporal lag between the onset of BD and hospitalization. Thus, it is too early to draw firm conclusions about the impact of lunar phases on BD. Sleep might be a middle way from moon effect to admissions of BD. These results have implications for future disease prevention strategies and research.

KEYWORDS:

• Bipolar disorder
• lunar phase
• hospital admission
• episodes of bipolar disorder
• retrospective study

Acknowledgements

The authors thank ZhumaDian Psychiatric Hospital, Beijing Huilongguan Hospital, and Shandong Mental Health Center for providing the data derived from patients with bipolar disorder. We thank Benjamin Knight, MSc., from Liwen Bianji (Edanz) (www.liwenbianji.cn) for editing the English text of a draft of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China under Grant [ID number 81574098]. The funders had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript. All authors state that this research was conducted independently of the influence of funding bodies.