People can get better over time, either because 'time heals all wounds,' or due to other things occurring in their lives during the course of the study. The authors performed a statistical test for this, but still, a control group would have helped to tease out how much improvement is due to the program itself, and how much due just to life going on. And since some study participants were receiving other treatments at the same time, there's no telling exactly what improvements are due exclusively to REACH. It is well known that when people invest a lot of time and energy in something, there's a psychological bias towards finding it worthwhile. This is true for researchers and participants, and is bound, in this kind of study, to influence the reporting and interpreting of results.
Of course, there's no reason to believe that it wouldn't work for a wider range of folk, since groups in general have been studied for over half a century now and the results are consistent. It works for nearly everybody, for nearly every problem. It's just that with this study, the authors could not claim with any certainty that this particular protocol would work for other than adult, straight, white males of a certain age.
The authors note that in a study of this sort, while you can say you're pretty sure the program helps, it's hard to say exactly what components of the program are most -- or least -- effective. That makes it a bit of a crapshoot whether you can replicate the results elsewhere. What if, for example, one of the only four psychologists running the study is just especially talented, and no matter what she did, her people would get better? On the other hand, if the standard curative factors of all effective groups were in operation here, you could do REACH or any other variation of multifamily group and get the same results anywhere. This is why we like to see multi-center studies, or studies replicated elsewhere producing similar results. However, when you are running only 4-6 vets and their families through at a time, and the whole process takes nine months, as this one does, we'd be waiting a minimum of four more years for the next study -- and that's not counting the time to organize and fund a study, write it up, and get it into print! So I think you will see a lot of psychologists running with this one, and soon.
participation in the REACH multifamily group program for veterans with PTSD and
their families. Professional Psychology: Research and Practice (44), 127-134.