The general rule is that students should avoid controversial topics such as politics, religion, and sex. Put mental illness and family traumas in that category also, for the most part. I've had students successfully write about some of these topics, but they've had professional guidance from me, the goal being to help the student express what they feel is important, without being off-putting and leaving a negative impression.
My student wants to write about converting to a different religion while in middle school, because she didn't like the attitude her previous religion had towards premarital sex and homosexuals. She's decent writer, and at no point does she say she is interested in premarital sex nor that she is homosexual. I am going to help her with the essay. She is very strongly committed to her topic, but I am also going to suggest she come up with an alternative topic to write about, because I think her essay is risky. If you understand the goal of essays and understand college admissions, when do you feel it's okay to write a risk essay?