Psychic Storms

Most of Druugheim experiences a unique weather event known as a psychic storm: in most ways resembling a powerful thunderstorm with wind and rain, but featuring purple lightning that leaves inanimate objects almost entirely unharmed, and wracks the minds of sentient beings.
A being struck by this lightning almost never dies in the physical sense. The worst victims are left as seemingly mindless husks, bodies of functioning but uninhabited flesh. These victims will continue to breathe, and will eat and drink if spoon-fed like an infant, but will take no action on their own, silently lying in whatever position they were last left. Without intervention by other people, these husks will die, either by thirst, exposure, or wildlife predation, as they lay helpless and inactive. In most of the cultures of Druugheim, these unfortunates are disposed of, with methods ranging from ritualized mercy killing to simply being discarded outside the settlement.
The majority of people struck by the psychic lightning have less extreme symptoms. While complete recovery is not unheard of, the vast majority of people come out of the experience with some kind of mental damage. Some go completely mad, others suffer various forms of amnesia, and many remain relatively intact, albeit with a new, comparatively minor, personality quirk or odd tic.
With nearly all of these storms blowing in from the northeast, there is much speculation that they ultimately originate in The Blasted Lands. Legends persist that a careful enough observer can see aberrant creatures moving around in the storm clouds if they're willing to brave the danger of the mind lightning.