http://www.collegedata.com/cs/data/college/college_pg01_tmpl.jhtml?schoolId=113
If you look at collegedata, assuming true, Providence emphasizes gpa, rigor and essay, not test scores. Clearly they did not like the essay topic, since your grades are in the range to make it a safety, as you say. Some schools may think you need extra resources that they cannot provide. By mentioning the diagnosis, some might interpret that way. There are schools that have specific resources for such issues and actively support you if you seek it, and others may view it as a burden. But even schools that actively support, would likely prefer to hear other things on the essay.