Who (if anyone) has done studies or work on the subject of the
psychological impact of litigation on ordinary litigants?  [I am NOT
interested in the psychological impact on lawyers, etc.]  What I am
trying to accomplish here is to identify psychologists, psychiatrists,
or related professionals who might prospectively become expert
witnesses concerning the devastating impact of litigation on ordinary
citizens who are sued.  I will welcome especially experts located in
or near Los Angeles, but may be able to use experts from anywhere in
the U.S.A.  I will probably need as many expert names
as I can get, because there are always problems [some people won't
testify, some are unavailable at the appropriate time, etc.].  Good
"Court credentials" [e.g., affiliation with University or hospital,
etc.] would obviously be helpful.  Also, I obviously would need some
way to get in touch with these experts [e.g., email address, or at
least their professional affiliation, so that I can track them down.] 
I would also like to know what, if any, books or articles these
experts have written.

One well-known expert on the effects of malpractice litigation upon
physicians is Sara Charles, M.D.:

Sara Charles M.D.
Professor of Psychiatry (Emerita)
University of Illinois School of Medicine at Chicago

www.facs.org/education/gs2003/gs50charles.pdf

"Medical malpractice claims have many adverse effects on physicians.
The most widely published expert on the topic, Sara Charles MD, has
found that more than 95% of sued physicians acknowledge some physical
and/or emotional reaction."

http://www.emedicine.com/emerg/topic760.htm

I very much appreciate the comments of pinkfreud-ga, and in a pinch
might use someone with the expertise to which she points.  I want to
make clear, however, that what I REALLY want is data concerning the
psychological and related impact on REGULAR PEOPLE [which is somewhat
different, and probably even greater than, the impact on persons
engaged as PROFESSIONALS [lawyers, doctors, etc.] against whom suits
are relatively common and expectable].  The ordinary person, however,
when hit with a completely unexpected and potentially ruinous suit
[e.g., multi-million dollar claims] is unlikely to be insured, and,
depending on the nature of the claim, may not be able even to bankrupt
out of any resulting liability.  It is the psychological impact in
those extreme circumstances which is of most interest to me here.

I posted the info above as a free comment because I couldn't find any
studies involving laymen who were subjected to litigation. That
doesn't mean that such studies don't exist, of course. But two hours
of searching failed to turn up anything useful.

I was outside my areas of expertise here. Perhaps a Researcher with
access to legal databases will be able to assist you.

This might interest you:

http://www.smu.edu/newsinfo/releases/01189.html