"Lunacy" - an adjective describing the effects of the full moon on human behaviour, including an increase in pathology, crime rates, violence, accidents and other psychiatrical disturbances.
From :
http://www.innerself.com/Astrology/full_moon.htmAt the University of Miami, psychologist Arnold Lieber and his colleagues decided to test the old belief of full-moon “lunacy” which most scientists had written off as an old wives’ tale. The researchers collected data on homicide in Dade County (Miami) over a period of 15 years — 1,887 murders, to be exact. When they matched the incidence of homicide with the phases of the moon, they found, much to their surprise, that the two rose and fell together, almost infallibly, for the entire 15 years! As the full or the new moon approached, the murder rate rose sharply; it distinctly declined during the first and last quarters of the moon.
To find out whether this was just a statistical fluke, the researchers repeated the experiment using murder data from Cuyahoga County in Ohio (Cleveland). Again, the statistics showed that more murders do indeed occur at the full and new moons.
Dr. Lieber and his colleagues shouldn’t have been so surprised. An earlier report by the American Institute of Medical Climatology to the Philadelphia Police Department entitled “The Effect of the Full Moon on Human Behavior” found similar results. That report showed that the full moon marks a monthly peak in various kinds of psychotically oriented crimes such as murder, arson, dangerous driving, and kleptomania. People do seem to get a little bit crazier about that time of the month.
That’s something most police and hospital workers have known for a long time. Indeed, back in eighteenth-century England, a murderer could plead “lunacy” if the crime was committed during the full moon and get a lighter sentence as a result. Scientists, however, like to have a hard physical model to explain their discoveries, and so far there isn’t a fully accepted one. Dr. Lieber speculates that perhaps the human body, which, like the surface of the earth, is composed of almost 80 percent water, experiences some kind of “biological tides” that affect the emotions. When a person is already on psychologically shaky ground, such a biological tide can push him or her over the edge.
http://www.innerself.com/Astrology/full_moon.htmFor a deeper, more spiritual understanding of how the full moon affects human consciousness, see Hilarion's explanation
*here*.