MentalHealthR Documentation

Mental Health Admissions


Admissions to a mental health emergency room and full moons


A dataset with 36 observations on the following 3 variables.

Month Month of the year
Moon Relationship to full moon: After, Before, or During
Admission Number of emergency room admissions


Some researchers in the early 1970s set out to study whether there is a "full-moon" effect on emergency room admissions at a mental health hospital. They separated the data over 12 months into rates before the full moon (mean number of patients seen 4-13 days before the full moon), during the full moon (the number of patients seen on the full moon day), and after the full moon (mean number of patients seen 4-13 days after the full moon).


Introduction to Mathematical Statistics and its Applications by Richard J. Larsen and Morris L. Marx. Prentice Hall:Englewood Cliffs, NJ, 1986.


The original discussion of the study is in Blackman, S., and Catalina, D. (1973). "The moon and the emergency room." Perceptual and Motor Skills 37, 624-626.