Holocaust survivors in Israel cope better with the traumatic effects of the genocide than those living in the U.S. and Australia, according to mega-analysis of prior studies performed by researchers from the University of Haifa.This is apparently a huge meta-study. Generally such studies are conducted because numerous smaller studies were inconclusive, and the results should be understood in that vein. Individual variation might be so great that this sort of aggregate data isn't very informative in most contexts. You can't tell without being an expert. Yet this strikes me as probably meaningful.
The analysis, carried out at the university's Center for the Study of Child Development, encompasses results from dozens of research works on some 12,000 Holocaust survivors living in the three countries.
The research found that living in Israel played a role in moderating the long-term effects of the Holocaust on survivors.
Tragedies, even more personal or local tragedies without anything like the magnitude of the Holocaust, destroy so much. Things that are hard for a lot of us to recognize, like a basic sense of integrity, control over one's own life at the level of the body. It should be obvious that political empowerment of the sort Israel provides would be meaningful to survivors.
The full story is at Ha'aretz. It provides conjecture on why this finding might be. There's also a note that the constant state of war Israel has been in might be a reason Isreal isn't more obviously good for survivors.