Lunacy and lunatic are words derived from lunar, because the issue of lunacy is tied to the moon. By extension astrologically natal moon placements and lunar transits. So I want to explore this a little bit possible hallmarks of lunacy.
Moon square Mercury: Emotions and thoughts clash, confuse the individual. Emotions will be expressed different than how they were felt. Also things may be taken in and processed incorrectly.
Moon in negative aspect to Pluto – Explosive emotions, need for power or control over others.
Moon in Pisces– Extremely sensitive emotionally also soaks up energies in surroundings quite easily. Intuitive and easily influenced by the moon.
Moon in Cancer– Home placement for the moon and the lunar transits have a huge impact here as well.
Moon in negative aspect to Neptune: Much like Moon in Pisces, easily soaks up the emotions in a way that personal emotions are hard to separate from the environment.
These are some of the potential natal placements, you will also have to check a lunar calendar and check when negative aspects from the transiting moon aspect your natal moon as well. These days may have you on edge somewhat especially with a water moon, so be sure to make an extra effort to keep a cool head. Peace.