It can go either way.

Sometimes serenity can result in a peak in creativity; sometimes it leads to a flatline where nothing is happening and there's stagnation and there's no inspiration or fire; kinda like how oysters need that grain of sand in order to start making a pearl. Same for mental turmoil and anguish; sometimes it makes people more creative, and sometimes it messes them up to where they can barely function, much less get into a creative headspace.