Often mentally ill people just do whatever the hell seems to feel good to them at the moment - masturbate , talk to people (we can't see), laugh at nothing, etc...I say wouldn't it be odd if they didn't scream?
My grandmother had Dementia for many years. The staff at the nursing home told my mom that grandma would MEOW really loudly during the night. The nurses would play tricks if a new nurse came on who didn't know about it. They'd let her/him go all over the floor searching for a cat until they found that it was my grandma meowing.
Also, AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!
I'm not sure why you are grouping everyone into one category of "mentally ill"? Someone who has depression is much different from someone who has schizophrenia, who is much different than someone who has dementia, who is - again - much different than someone with a traumatic brain injury. To ask why "mentally ill" people scream is kind of like asking why physically ill people feel pain. There are a multitude of causes for screaming - or pain - and not everyone with a mental illness screams. Its just too general of a question to properly answer.
AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
to understand this, I would suggest anyone reading think about what types of feeling and emotions would provoke screaming in them. I would imagine that those types of emotions are the same ones that make mentally ill people scream as well, although what provoked the emotion itself may not be sufficient to invoke the same emotions in a normal person. emotions the same, the emotions may be inappropriate for the situation but the feelings are the same.
Janov's book The Primal Scream changed my whole way of thinking. Some scream because of tourette syndrome.
Me too, in a way, and for a while, but regressive therapy is dated an not scientifically sound. Obviously we are a product of our environment and how we were brought up/what has happened in our lives will shape up, but re-visiting these traumatic experiences over and over again can simply strengthen the neural pathways that are responsible for the "problem" in the first place. Psychology is now moving towards creating and strengthening positive ones instead. You can't just "purge" traumatic experiences. That's just not how the brain works.
I absolutely screamed my head off the other day at two people the other day who were speaking Creole French very loudly below my room.They were at it for about 45 minutes and I was already suffering stress from hearing voices all day,having been up all night on a stimulant.I am officially diagnosed with paranoid schizophrenia which sounds scary,but I lose my temper very rarely,have insight into my condition,and can act normal when required.
I think it depends on what disorder you have - some people might be having scary hallucinations, some people might be having an anxiety attack and think they're dying. For me, I have bad impulse control, so I get really frustrated (sometimes for no reason) and I get such a strong urge to scream it's like I just can't stop it.