A lot of the points he made are wrong. Shell shock is physical damage to the grey matter of the brain, caused by an explosion. PTSD is mostly psychological and can be caused by shell shock.
"Shell shock is a word that originated during World War I to describe the type of post-traumatic stress disorder (PTSD) that many soldiers experienced during the war, before PTSD was officially recognized."
"Shell shock is a word that originated during World War I to describe the type of post-traumatic stress disorder (PTSD) that many soldiers experienced during the war, before PTSD was officially recognized."