I have a lot of ideas about what i want to write for my common app essay. After reading forums and talking with peers, the consensus seems to be that you need to write about a significant personal experience that changed the way you look at the world or made you into the person you are today. During my freshman year, I battled depression and self harm, which was heavily connected to school stress. However, through help from friends and therapy and my own willpower, I recovered. My grades never suffered as a result of this and the next year I continued to take challenging AP classes. The whole event had a huge impact on me and made me realize the importance of self care and knowing your own worth. This story is extremely close to me, and I am wondering if writing about this topic would be oversharing with the admissions officers, especially since some might see my past as detrimental and believe i am not capable of handling the rigorous course work of the university. Last summer, I went on a service trip to Costa Rica and had an amazing experience living with a host family and learning about the privileges we have in the US and the resilience of people living in poverty. My uncle was also diagnosed with brain cancer last year and that experience has gotten me interested in healthcare policy and created a new intellectual interest as well as social justice cause. Both could make for good essays. I have something to say about each topic but I am wondering if any one would help me stand out more in the highly competitive admissions pools. Looking for any thoughts on which one I should pick?
The idea that stands out to me the most is the final one about your uncle! It would allow you to demonstrate your academic/intellectual interests through the lens of a personal story, so you get the best of both.
Will your story of depression be seen as oversharing? It really depends on who reads it and how it’s written. You may not want to take the risk of it being seen in the wrong light. It could still be a powerful essay topic if you choose to pursue it - if I were you, I would write a draft and solicit feedback before deciding.
The only one of these I would absolutely not write about: your service trip. It sounds like your experience was wonderful! That said, college admissions officers read approximately a billion other essays about similar trips. It’s a very popular topic, and everyone has a similarly humbling takeaway from their experience. You want to write the essay that only YOU could write. That will make you stand out in any admissions pool. Best of luck!
Keep in mind the purpose behind the essay: it’s to make the reader want to have you on his or her campus-- to “give them a reason to say yes.” It’s not therapy, it’s not confession.
Personally, I would avoid the first topic. The reader is bound to wonder just how recovered you are and whether a relapse is in your future.
As for number two: you only have 650 words. Make sure your essay is about YOU.
Thanks for the advice both of you 
I’m going to go with the uncle story. I was on the fence about writing about the first topic anyways and I think I was mostly influenced by an article I read about someone who wrote an essay about their abusive parent and was accepted into 8 of the Ivies. But I know this essay is supposed to be about me and my story so the third choice it is.