How is PTSD related to the concept of shell shock?

Shell shock is a term coined in World War I by British psychologist Charles Samuel Myers to describe the type of post traumatic stress disorder many soldiers were afflicted with during the war (before PTSD was termed). ... During the War, the concept of shell shock was ill-defined.

what the first or next guy says

no options provided, here,but the answer to this question is often: a historian cites a japanese newspaper article published a year after the end of world war ii in order to draw conclusions about the effect of the war on the japanese economy.

clearly from the answer, the historian alludes to historical sources,and records to aid in analyzing and drawing conclusion on the effect of the war on the economy of japan.