As a diagnosed schizophrenic who's had a few psychotic breaks over the years I could totally relate to this movie...
Iv'e experienced something similar { Not to this extent though } where something real was happening in my life 7 years ago and nobody believed me, and I was doubting myself in the end, but it turned out it really was happening to me and I was a victim of one of my neighbours who didn't want a schizophrenic living next door to him and I was being victimised, but only when nobody was around.
The script writing, direction and acting were all top shelf...
Whoever did the research did it extremely well....