That is subject with many changing names over the years -
Battle Fatigue in Civil War,
Shell Shock in WW-1 and WW-2
were names before PTSD.

https://en.wikipedia.org/wiki/Siegfried_Sassoon

https://en.wikipedia.org/wiki/Wilfred_Owen

the two above were extremely brave, highly capable writers, who described in writing recovering in special WW-1 hospitals for Shell Shock.

One of my high school history teachers who was a Marine veteran of Guadalcanal required his teenage students to read the poems and letters of Sassoon and Owen.

He also assigned us reading about the incident with General George Patton and a hospitalized soldier.

Vets report that the condition can re-appear decades later:

https://medicalxpress.com/news/2021-10-veterans-distress-trauma-exposure-life.html

I would suggest starting by looking into all the older names to get leads on how family members have discovered beneficial treatments.

https://medicalxpress.com/news/2023-06-qa-battlefield-broader-post-traumatic-stress.html

I can say from personal experience that 1970s coal miners often brought up the subject during lunch break and I have witnessed Korean War vet foremen “guiding” Vietnam vets toward coping strategies.