Comment on Roy's "Alcohol misuse and posttraumatic stress disorder (delayed): an alternative interpretation of the...

The statistical methods used by Roy to compare veterans who served in Vietnam with Vietnam-era veterans who did not serve there are questionned. His method of pooling means is considered improper and his data are considered incomplete because they do not relate to alcohol use in veterans with posttraumatic stress disorder. Roy's argument that the military is not liable for problems caused by predispositions is questioned.