My father recently had a ICH stroke and then underwent clipping of a brain aneurym 4 weeks later. Physically he is doing wonderful, but mentally he goes through phases of paranoia, anger, confusion, disorientation etc. They are telling me that this may be a psychosis due to surgery? Almost 85% of the time any conversation makes absolutely no sense and he also can't focus on tasks but will become obsessed with other things such as finding flashlights or the cat?