A lunatic (colloquially, "loony") is a person who is mentally ill, traditionally someone whose sanity comes and goes with the phases of the Moon.
This probably refers to the symptoms of what is now known as Bipolar disorder.
Extremely foolish persons are also called lunatics.
... wide, with an area of 78,000 km² (24,560 sq. miles). The capital of Sakhalin is Yuzhno Sakhalinsk[?] (Japanese: Toyohara (豊原)), a city of about 200,000 ...