"Achilles in Vietnam" by Jonathan Shay. I agree it's quite good. IIRC, the author was a doctor in a VA clinic for Vietnam vets suffering from PTSD, and he was

"Achilles in Vietnam" by Jonathan Shay. I agree it's quite good. IIRC, the author was a doctor in a VA clinic for Vietnam vets suffering from PTSD, and he was struck by the similarities between their condition and descriptions in the Illiad