The first anime I ever properly watched was Another. You can understand my reluctance in watching anime for a while after. Really...the deaths were horrific. One teacher stabbed his throat in front of the class, a girl was pierced in the throat by her umbrella after having fallen down stairs, a nurse was smashed to bits when her elevator plummeted in free fall, a boy died from an asthma attack, another died from a heart attack, I believe a boy was smashed in the head by a pipe or axe, the protagonist had a dream in which his face literally rotted beneath his hands, a teacher was caught under a tree then killed by an axe or something, some images of bodies with shards of glass in the skin, someone died in a lightning storm, the brother of a student was killed when a mechanical digger lost control and smashed into his room, and the entire premise is about two main students trying to find the vengeful ghost who instigates all the death.
I have not revisited this anime for a year. I still remember all this, so I believe it has somewhat traumatised me.