Maniacal

Stefan's maniacal laughter was ringing in Amelia's ears.

In other cases of moral alienation there will be found to have been more or less congenital moral defect, with maniacal exacerbations of positive moral insanity occurring perhaps at puberty, perhaps at the menstrual periods, perhaps after severe disappointment.

He suddenly exploded into about three seconds of maniacal laughter and stopped again.