I have worked with severe PTSD in Veterans and trauma experiencers with near 100% resolution.
The key is to find the initial perceptual programming event that predisposed the person to PTSD. Often this happened in early childhood.
I have the advantage in that the stored traumatic memories are physical objects to my perception. The person need not say anything. They merely think of the trauma and the stored memory of the event becomes physical to me. There are several techniques using plasticity to reprogram the stored memory and remove the intense emotion attached to the memory.
This also works very well when working with victims of violent rape.
100% resolution?
In other words the constant state of alertness is gone? The exaggerated response to an unexpected noise is gone? The constant checking out of a new area for oddities is gone? The alertness to unexpected odors is gone?
There’s a horde of personality oddities combat PTSD people acquire. I just cannot see them all going away.
But then again the VA’s definition of 100% may differ from those that actually have PTSD.