Disclosing ADHD

Does disclosing the fact that I have ADHD in my essay hurt me. I got deferred from a really easy college, even though my ACT is a 35 and GPA is a 3.5. In my essay I explained how having ADHD has affected my GPA, and how once I was diagnosed/medicated my final average increased 12 points and GPA increased 3 points.

I know that colleges aren’t supposed to discriminate against people who have ADHD, but do they still deny people simply for having it?

My S had the diagnosis, and I would not recommend to write about that on an essay.
They are looking for unique personal interests, accomplishments, experiences, thoughts.
ADHD diagnosis is not as unique as it once was, and likely came off as being overly focused on grades.

Colleges do look for an upward trend in grades throughout HS, the reason you should leave them to assume
you became a better student, however you accomplished that.

Of course they should not discriminate, but a high ACT is no guarantee of admission.
What college is it that you think is so easy to gain admission. Many people with such high ACT
scores think anything other than Harvard/Yale/Princeton is “easy” to get in. Not true of many colleges.

Providence- 55% acceptance rate
It was a safety for me
@blevine

ADHD is very common, and you would not be discriminated against for this reason. However, if your “explanation of lower grades” came off sounding like you were making excuses, that would be a problem. Also, as @blevine said, the essay is your opportunity to reveal the things that make you unique that will give colleges an idea of the value that you will add to their campus. The ADHD/grades explanation does not belong there. If you feel that you would like to have this issue addressed, better to have your counselor address it independently.

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.