Middling...
Middling movie... Relies so much on McAvoy to elevate it, but nothing he can do is able to raise this above the late night UK TV feel and aesthetic...
Lacks mood and atmosphere... There is no sense of how much he's lost his mind, how it feels, rather it is shown with the whole pills, doctor sessions and such... There are detective crime movies that do it so much better, for example Shutter Island, which is set in an asylum for the criminally insane... as well as dramas like Take Shelter...