As a transfer student, should I explain the struggles I had in high school and where should I if so?

People tell you to write the personal essay (common/coalition essay) about something personal that only you could write about and that shows a piece of your story that would be missing from your application otherwise. I've also heard that you should make sure the story you tell is one from a recent part of your life. However, applying as a transfer student from a community college, I'm thinking about how depression and anxiety intensely affected me during high school, and I'm worried about the fact that admissions officers won't know that when they're looking at my high school transcripts. (I didn't do terribly, but I didn't do very well; I think I had like a 3.3 or something, and I have a 3.9 from my community college.) I was wondering if I should write about that, as long as I can do it well and still emphasize something about my character or a learning experience, or if I should forget about trying to explain any part of high school because it's been a few years since I graduated. Should I write about something more recent for that essay and somehow talk about/mention how depression and anxiety affected me in high school elsewhere in the application (and if so, where)? Or should I forget about talking about/mentioning it all together? I'm planning on applying to some very competitive universities.