I think the mecjanism for screaming (now this is my opinion only) it feels like i have this ball of intensity inside me and it's swirling around, and can't get out. and weather it's symbolic or not screaming yelling actually gets it out and pacifies me. (probably psycological, which everything is hunh) but i deal a lot in anger problems and yelling really pacifies me. i think to be heard or to hear yourself, just does something to the psyche and evens you out. go to the park and go wild no one cares how much noise you make there or into a pillow, but actually hearing it works. well for me anyways....everyone is different. can't hurt to try!