10 Most Underrated Psychological Horror Movies

Almost entirely free from onscreen violence, Brad Anderson's 2000 film Session Nine is a triumphant example of how much an effective psychological horror can achieve through intense and unsettling atmosphere alone.

This creepy asylum-set flick never got the critical re-evaluation it deserved, despite the director's later successes in the sub genre with the Christian Bale vehicle The Machinist and 2014's underrated period mystery Stonehearst Asylum (seriously, what is it with this guy and haunted asylums?).

Session Nine follows an asbestos clean up crew as they clear out an abandoned asylum, with its story simultaneously slowly revealing the fate of one unfortunate patient who once lived within its walls.

The film is slow, deliberate, and unsettling, and its almost entirely male cast of labourers make for an unexpected set of horror movie characters. Self consciously tough and unflappable, the men's collective growing unease serves to make the film all the scarier as they seem as much a threat to each other as any external force.

Elevated by some stellar performances and a killer twist, this one is not to be missed by fans of the genre despite its underwhelming initial assessment upon release.