This poem also owes its existence to W.H.R. Rivers. He was a notable individual. His early research was in anthropology and neurology. He was a key figure in the early treatment of what is now called PTSD, and a lead medical officer at Craiglockhart.

Another poem from Craiglockhart is Sassoon's "Repression of War Experience." It is one of the relatively uncommon works, both as literature and clinically, that depicts the sensory experience associated with PTSD. https://www.poetryfoundation.org/poems/57267/repression-of-w...

Incidentally, Rivers himself also wrote a paper titled "The Repression of War Experience." It was published in The Lancet around the same time. https://archive.is/EZerl

A century later, I believe the poet's attempt was more successful than the scientist's in sharing the data.