For a deep dive into how "flashbacks" have shifted from a drug-culture term to a psychiatric staple, the most interesting paper is (Jones et al., 2003).
It wasn't until the Vietnam War era and the 1980 inclusion of PTSD in the DSM-III that the flashback became the "hallmark" symptom we recognize today—defined by a vivid, sensory "here-and-now" reliving of events. Flashbacks! Evolution!
The term "flashback" was originally coined in the 1960s to describe the recurring visual hallucinations experienced by LSD users . For a deep dive into how "flashbacks" have
When researchers examined medical records of UK servicemen from the Boer War and World Wars I and II, they found that flashbacks were virtually non-existent . Instead, soldiers then expressed trauma through physical symptoms (somatization) like tremors or "effort syndrome". When researchers examined medical records of UK servicemen
Flashbacks and post-traumatic stress disorder: the genesis of a 20th-century diagnosis. National Institutes of Health (.gov)
The authors suggest that the prevalence of flashbacks in modern veterans might be influenced by technological advances (like cinema and televised war footage) that have shaped how we "visualize" and store traumatic memories. Other Noteworthy "Flashback" Research
If you're interested in the or modern clinical definitions, check out these papers: Flashbacks and post-traumatic stress disorder - PubMed