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THE ASSOCIATION OF LUNAR PHASES AND MENTAL ILLNESS: FACT OR MYTH?

KY Loh MMed(FamMed UKM),  International Medical University, Seremban, Malaysia

Address for correspondence: Dr Loh Keng Yin, Senior Lecturer, International Medical University, Jalan Rasah, 70300 Seremban, Malaysia. Tel: 06-7677798, Fax: 06-7677709, Email: kengyin_loh@imu.edu.my

Loh KY. The association of lunar phases and mental illness: fact or myth? Malaysian Family Physician. 2007;2(1):44

Since ancient times, human has been fascinated by the changing lunar phases – a monthly cycle that takes 29.53 days to complete (Figure 1). Many cultures in the world hold the beliefs that the changing lunar phases affect human behaviour; in particular, full moon has been associated with madness. The word “lunatic” (previously used to mean mentally ill) came from Latin lunaticus which in turn was derived from luna meaning moon.¹

Fig 1: The changing lunar phase. Photographed by the author. Technical information: Nikon Digital SLR D70 combine with Meade LX 90 computerized telescope. Photo processed with Adobe Photoshop Elements.

The presumed association between lunar phases and human behaviour has been a subject of scholarly research. Templer and Veleber in 1981 claimed to have found a disproportionately higher frequency of abnormal behaviour at the time of the new moon, full moon and in the last half of the lunar phase. The authors regarded these findings as generally congruent with folklore.² However, observational studies conducted before or after him were mostly equivocal:

• Jones et al did not find increased suicide rate during full moon when they documented 928 cases of suicides in a 4-year period. In fact, there were more suicides noted during the new moon.³
• Gerlock et al found no relationship between seclusion of psychiatric patients in a university hospital and lunar cycle.⁴
• Cohen-Mansfield did not find significant association between agitation behaviour in nursing home and lunar phases. In fact agitation was actually less often during full moon.⁵
• Ammadeo et al did not notice increased number of contacts with community psychiatry based-services with moon phases in a 10-year period.⁶
• Owen et al failed to establish an association between any lunar phases and violent behaviour.7
• Wilkinson’s study showed no statistical significance in the lunar influence on anxiety or depression consultation in general practice.⁸
• Barr looked at the influence of the moon on mental health and quality of life. He found significant change of behaviour occurred at the time of the full moon only in subjects diagnosed with schizophrenia.⁷
• McLay et al evaluated the effect of lunar cycle on psychiatric admissions or emergency evaluations – no significant association.⁸

In conclusion, the majority of observational studies demonstrated no significant relationship between human behaviour or mental illness with the changing lunar phases.

References:

1. Concise Oxford Dictionary, 10th Edition. Oxford: United Kingdom, 2001.
2. Templer DI, Veleber Dm. The moon and madness: a comprehensive perspective. J Clin Psychol. 1980;36(4):865-8 [PubMed]
3. Jones PK, Jones SL. Lunar association with suicide. Suicide Life Threat Behav. 1977;7(1):31-9 [PubMed]
4. Gerlock A, Solomons HC. Factors associated with the seclusion of psychiatric patients. Perspect Psychiatr Care. 1983;21(2):46-53 [PubMed]
5. Cohen-Mansfield J, Marx MS, Werner P.   Full moon: does it influence agitated nursing home residents? J Clin Psychol. 1989 ;45(4):611-4 [PubMed]
6. Amaddeo F, Bisoffi G, Micciolo R, et al. Frequency of contact with community-based psychiatric services and the lunar cycle: a 10-year case-register study. Soc Psychiatry Psychiatr Epidemiol. 1997;32(6):323-6 [PubMed]
7. Owen C, Tarantello C, Jones M, Tennant C. Lunar cycles and violent behaviour. Aust N Z J Psychiatry. 1998;32(4):496-9 [PubMed]
8. Wilkinson G, Piccinelli M, Roberts S, et al. Lunar cycle and consultations for anxiety and depression in general practice. Int J Soc Psychiatry. 1997;43(1):29-34 [PubMed]
9. Barr W. Lunacy revisited. The influence of the moon on mental health and quality of life. J Psychosoc Nurs Ment Health Serv. 2000;38(5):28-35 [PubMed]
10. McLay RN, Daylo AA, Hammer PS. No effect of lunar cycle on psychiatric admissions or emergency evaluations. Mil Med. 2006;171(12):1239-42. [PubMed]