Adjective

What is the cause of insanity?
Nobody can answer such a sweeping question as that,
but we know that certain diseases, such as syphilis, break
down and destroy the brain cells and result in insanity. In
fact, about one-half of all mental diseases can be attributed
to such physical causes as brain lesions, alcohol, toxins,
and injuries. But the other half—and this is the appalling
part of the story—the other half of the people who go in-
sane' apparently have nothing organically wrong with
their brain cells. In post-mortem examinations, when their
brain tissues are studied under the highest-powered micro-
scopes, they are found to be apparently just as healthy as
yours and mine.
Why do these people go ' insane ?