Dear Lobz~
Welcome here to the Forum. I guess from my point of view a therapeutic separation is different from a trial separation. The aim is to get back together. It can be an opportunity to miss each other.
I would think for it to work both peple would need to want it and there should be rules and agreements. Such things as how long it lasts, who is responsible for what, is intimacy with others allowed, what to tell the kids and so on.
For someone who has PTSD this could I suppose lessen trust, or make it stronger. In my own case (I have both PTSD, bouts of depression and an anxiety condition) I think it might make it stronger if there was no outside intimacy and all agreements were met.
On the other hand for someone wiht anxiety it may be a very difficult time wondering about what will happen.
The outcome might be to let each person know what living apart is like, and hopefully get back together appreciating each other more and at the same time letting the other person know tactfully what will make things easier. Your mental health conditions may make this more difficult and need sensitive handling.
That is perhaps a rahter rosy picture, so may I ask what you want and what you would see as the advantages and downsides?
In closing I think most marriages or partnerships have ups and downs and go though rough patches as well as happy ones
Croix
