Usage patterns
狂気に陥るto fall into madness
He fell into madness out of sheer loneliness.
狂気を帯びるto take on a touch of madness
His eyes had a touch of madness in them.
狂気に満ちた〈事〉an act/scene filled with madness
It was a plan filled with madness.
Expressions
狂気の沙汰crazy deed; act of sheer madness; the height of madness