I watched a psychological thriller last week also in my quest to watch as much sub-genre thrillers.
I watched my favourite Psychological thriller Phone Booth. This thriller at all times when he is in the phone booth at the edge of your seat and you do not know what is going to happen next if he does get shot or survives. He is also battling with another mind and this is what psychological thrillers are about. Here is an example of what I am saying.