Question on prompts

Answered

I'm not sure what platform you are using to submit your applications, but I know that the CommonApp has a seventh prompt that allows you to choose your own topic, presuming that is the main problem.

That being said, if its more of an anecdote (of lack thereof) problem, then there's a solution to that as well. I personally found the "21 details" exercise very helpful when conceptualizing my essay. Basically just think of 21 things that describe yourself or your interests. You can list your favorite band, someone you look up to, what you ate for dinner last night, best/worsts habits, etc. Generally speaking, once you get about halfway through, you'll come up with stuff you probably weren't thinking of before. Then when you're done, look at them. Is there a common theme? Which topic on your list could you talk about for hours? Does your heart flutter when you look at one point in particular? If so, that means you're probably passionate about it. Passion is the key to a good essay.

Admissions officers look at hundreds of essays per week, many of which are dull or cliche, so you need to be the applicant that pulls them out of their mind fog, regardless of the actual subject being discussed. The College Essay Guy and ElevatED are a few excellent resources to reference when outlining your essay, especially if you're stumped. However, even if you don't talk about your major in your personal statement, as that's perfectly fine, I would suggest expressing the reason(s) for wanting to pursue neuroscience/biomed in the supplemental essays, especially if your ECs aren't fully reflecting your enthusiasm.

To answer your question directly, no I would not worry too much about this. While I would definitely be mindful of cohesion, having diverse interests can actually be a benefit to your application if framed well. I hope you don't mind this answer being so long, and best of luck to you with your applications!