Unit cohesion and homecoming support are examined for their protective
effects on the development of posttraumatic stress disorder (PTSD) an
d other psychopathology. Data on 1198 male theater veterans were taken
from the National Vietnam Veterans Readjustment Study. Unit cohesion
had no significant relationship, as a direct effect, to either PTSD or
other psychopathology. Ln a pattern that was Opposite to predictions
from the buffering hypothesis of support, however, a high level of uni
t cohesion in combination with high war zone stress was associated wit
h the highest levels of PTSD and psychopathology. This is consistent w
ith Israeli experiences, suggesting that unit cohesion may have detrim
ental long-term effects on psychological well-being. In contrast, home
coming support was related negatively as a direct effect to both PTSD
and other psychopathology. In addition, interaction results, consisten
t with the buffering hypothesis, suggest that the protective effects o
f homecoming support are magnified for veterans with high compared wit
h low levels of exposure.