Today, in the entry for lunatic:
The word is borrowed from Latin"lunaticus", which gains its stem from "luna" for moon, which denotes the traditional link made in folklore between madness and the phases of the moon. This probably refers to the symptoms of cyclic mood disorders such as bipolar disorder or cyclothymia , the symptoms of which may also go through phases. As yet there is little evidence for any causal link between phases of the moon and the progression of mood disorder symptoms.You probably knew that already. But then,
In a 1999 Journal of Affective Disorders article, a hypothesis was suggested indicating that the phase of the moon may in the past have had an effect on bipolar patients by providing light during nights which would otherwise have been dark, and affecting susceptible patients through the well-known route of sleep deprivation. With the introduction of electric light, this effect would have gone away, as light would be available every night, explaining the negative results of modern studies. They suggest ways in which this hypothesis might be tested.Yes! Test that hypothesis! Bring back lunacy!