You can't talk psychological terror in gothic without starting with 'The Turn of the Screw'. It's this masterful, claustrophobic thing where you're never sure if the governess is seeing real ghosts or if the horror is entirely inside her crumbling mind. The ambiguity is the whole point—it weaponizes the reader's own doubt. That creeping uncertainty is so much more effective than any overt monster.
A more modern, and honestly brutal, take is Shirley Jackson's 'We Have Always Lived in the Castle'. The psychological terror there isn't about ghosts; it's about the warped reality of Merricat, the narrator. You're living inside her paranoid, ritualistic worldview, and the true horror dawns slowly as you piece together what her family actually did. It’s a quiet, seeping dread that settles in your bones.
Then you’ve got the classics like 'The Haunting of Hill House', which is a textbook study of a vulnerable psyche being consumed by a place. Eleanor’s descent isn’t just about scary noises; it's about her desperate need to belong somewhere, even if that somewhere is actively destroying her. The house mirrors and amplifies her own instability.