Maybe I'm over simplifying things, or maybe I've completely misunderstood. . . . ( this is just my thoughts, take it, or leave it)
The decision should be based on whether you want this to be solely a PTSD forum, or a much broader 'trauma' forum, encompassing every possible diagnosis surrounding trauma?
now 3 diagnoses plus a zero symptom general trauma and stressor diagnosis makes up the new category which all have the cause in common, being a stressor or trauma.
So you're not just talking about encompassing AD into the forum but other diagnosis' too? I have to be honest, I can see more negatives than positives in doing that.
I can see why you have said that you don't want the forum to be left behind, but I don't agree that is the case. I would say that it is good to have a specialist forum for one specific trauma diagnosis. It means that everyone here is understanding things from the same view point. If you throw a whole host of different diagnosis' together, then the forum will become somewhat 'watered down'.
You already deal with some of the different types of stressors by providing My combat PTSD, and My sex abuse forums, (and I believe coming soon - a domestic abuse forum). I don't know about the other forum(s), but My sex abuse is open to non-PTSD sufferers to discuss their trauma.
I genuinely think that when people who are suffering search on line for support, they search for their specific issue, in order to contact others who understand their disorder.
As an example if you suffer from multiple sclerosis, you would look for that rather than just general neurological disorders.
If you were to go down the route of changing the forum to 'general trauma', then you would likely need a lot of subsections for each of the various diagnosis'.
If you were to shift the focus from symptoms to trauma types then you make the other existing forums (Combat, SA, DV) defunct.
At the end of the day, this is your forum, and only you can decide whether you want it to be the leading forum for those diagnosed with PTSD, or whether you want it to become a general trauma forum, encompassing all trauma (big or small), and every possible diagnosis that could result from that.
I'm not against change, but I think this a huge decision for you to make. Because once made, there will be no going back.
There is something to be said about specialising in one subject rather than becoming a 'jack of all trades, master of none'.