Malcolm Sage and Sir James between them succeeded in placing young Dane more at his ease. The haunted, shell-shock look left his eyes, and the twitching
disappeared from the corners of his mouth.
The term ‘shell-shock’ was originally used (1n 1915) to mean a psychological disturbance suffering from exposure to shellfire. Later it was expanded in general usage to include any psychological damage caused by war. The writers of the 1922 report of the War Office Committee of Enquiry into ‘Shell Shock’ (the Southborough Report) put the word into quotation marks and regretted having to use it, because it was ‘wholly misleading’ but
unfortunately its use had already been established and the harm had been done. The alliteration and dramatic significance of the term had caught the public imagination, and thenceforward there was no escape from its use.
Herbert Jenkins in his detective story is using the term in a completely non-military context, to describe someone who has suffered an emotional upset. The OED does not give this kind of usage of the word until the 1970s, and the examples given seems to be deliberate hyperbole, perhaps not to be taken seriously:’ Seeking relief from this shell-shock, I phone a screenwriter friend.’ and ‘The student was shell-shocked by the letter.’ (both examples 1978).
I’d be interested to hear of any other sightings of the term in a non-military context in the twenties or thirties.