With all due respect to the above posters I have had a positive experiance with teaching Aikido to veterans with stress related disorders such as PTSD.
The syllubus is highly modified and features Aikido's Spiritual and nonagressive aspects of conflict resolution...
I however personally feel that a practice such as Tai Chi or similiar art would be more beneficial, and my suggestion would be to approach someone like Mike Sigman who is both a Vietnam Vet and expert on Chinese IMA.
I like what you're saying here William.
In addition to conferring with William Hazen, you might consider reading In Search of the Warrior Spirit: Teaching Awareness Disciplines to the Green Berets by Richard Strozzi Heckler. It recounts Heckler's experience teaching an Army-sponsored experimental course. These were not students with PTSD, but the questions and issues that arose during that course might help you anticipate some issues that might arise during the classes you're planning to teach. If nothing else, it's a great book.
I'll second the recommendation of reading that book.
My experience in "working" with those suffering from PTSD comes from two different perspectives. My Father was severely abusive to me as a child. I believe aikido, as it was taught to me by my sensei, has been very helpful in dealing with the emotional baggage that accompanies abuse.
The second perspective comes from working with Marines (in the same office/location) in my job. I work for the Marine Corps in a capacity unrelated to mental health. I believe that our current health professionals are throwing far too many medications at these individuals in an attempt to help them. Personally I think if they discover alternate means of dealing with the stresses they will be better off in the long run. I believe aikido approached in the right manner, as William has mentioned, would be beneficial, and if nothing else, would keep them out of the bars.
Good luck to you Thomas.