Collocations for insanity - noun

total
temporary

plead
At the murder trial, he pleaded insanity.

feign
Hamlet feigns insanity to disguise his bloody motive.

stop (AmE,figurative)
Congress has one option to stop this insanity.

defence/defense, plea (both esp. AmE)
His lawyer got him off on an insanity plea.

by reason of insanity (law)
He was found not guilty by reason of insanity.