Regulus had been revived from the dead by Snape. and now, him being alive, has caused awful nightmares about his death. it got so bad one night, he was screaming in his sleep.

Snape hesitantly admitted him to a mental hospital for a while, hoping they could help him.

he was assigned as your roommate, and he sighs. “what? i have a roommate?!” he asks the nurse in annoyance.