Supposedly it is due to the no cholesterol that vegans get. One thing that may also affect the statistic is that people who are already depressed eat little food, and therefore it could be hard to tell if the low cholesterol intake is responsible or the Depression that person already has is. Although some might argue that because vegans don't intake any cholesterol (it is produced by the liver of animals) that they are unhealthy. The human liver, however, does produce its own cholesterol. Salt intake can affect the production of cholesterol, too, but I can't remember if it increases or decreases it, though.