Sex difference in response to stress by lunar month: A pilot study of four years' crisis-call frequency

BACKGROUND This study is in response to the question of whether the moon can influence daily levels of stress. METHOD Four years of telephone-call frequency data were obtained from a single crisis-call centre. We used the method of lunar-day numbers 1 to 29 for analysis. We also tested the concept of 'strong moons' as occurring when the Sun was near to the lunar-node axis. RESULTS An increase in calls was recorded from females and a decrease in calls by males during the new moon period, suggesting a sex difference in response, and there were proportionally more calls by males a fortnight later. A comparable swing in the male/female call-ratio on a weekly basis over Fridays and Saturdays was noted. Limitations of staffing at the call-centre prohibited comment on seasonal correlations. CONCLUSION Lunar-related studies of stress should endeavour to separate the data by sex or the effect can be lost. Distress-calls by women were more strongly linked to the lunar month than were those by men.