Take any input as well intentioned critiques formed from incomplete information.
OP, you really need to write a full rough draft of your essay on this topic before basing your course of action on any critique herein. (Of course, you do not want to post a full draft on a public forum.)
One’s topic can appear to be appropriate, but it’s the execution and delivery of the writer’s thoughts that is important and will, in your case, determine whether or not your topic is appropriate and effective.
That’s your essay - write about that!
Keep in mind that the college essay should not be considered a “soul baring” exercise. You want to give admissions officers a glimpse into something about you that may not be apparent on the application and, most importantly, you want to give them a reason to get excited about having you as a student at their college.
Agree with the advice to start with an outline or rough draft and see how it goes. FWIW, CC has people who would be willing to read the essay and provide advice.
I would love to read about deep sea creatures, which was a prelude to all the other things (including the human brain) you find fascinating.
Keep the focus off ketamine and on to YOU and it will be authentic and interesting!
A professor who I know once told me that he thinks that all of the academically strongest and smartest students he had dealt with have at some point suffered from some sort of depression or something related to this. “All” is probably an exaggeration. However, this is far more common that a lot of us want to recognize. This also can be common among the most accomplished and famous people. There are at least two things that come to my mind: The most accomplished and famous people are not always “average”, and may have grown up being the odd kid (until they started getting known for whatever eventually made them famous). Also, it is not easy being famous. For example the expectations are high and don’t go away. This last point might be less bad for scientists and engineers, and worse for people who are in entertainment who can’t just walk down the street without being recognized.
There is still some stigma, but I think that it might be a bit less than it used to be.
By the way, there is similarly a stigma about cancer. However, some famous people have recently been willing to talk about it publicly and I think that this helps. I posted something related to this in the “bragging” thread a few weeks ago. As more of us live longer either with cancer or after beating cancer the stigma may go away a bit, or at least be less intense.
There are however a lot of people who are being helped in a very significant way. The hope is not always false.
Some of those “real scientists” are themselves being helped in this area (see first point above), and are living good lives and having good relationships at the same time.
Of course pharmacology can be useful in ways outside of neuroscience. For example, someone I know was at some point working on trying to improve treatments for a gene-based illness. She was working with biochemists who were trying to find drugs that would bind with a particular hormone to turn it off (there are some cases where turning off a hormone can be medically useful). This had nothing to do with the brain, other than helping to make people healthier.
To me it seems that people who are very successful often have a tendency to go a bit overboard, whether in their work or their personal life. They are interested in completely understanding an issue, and sometimes in seeing how far they can take something. Two people I know who were very successful in high tech have decided to see how far they can go in music (one to the point of going back to school to get a four year bachelor’s degree in music from a well known music school). I might have personally gone a bit overboard in terms of growing blueberries – this has nothing to do with my career, it is just the way that some of us operate. One high tech person I know also races sailing catamarans. This might come from a desire to understand how things work, and perhaps from the ability to do well enough to compete semi-successfully in a range of fields.
I hope that all of this is helpful to you as you think about what to write.
OP…there is a stigma attached to the measles vaccine, stem cell research, life saving interventions for ectopic pregnancy, even evolution in some circles. Surely there are other reasons the topic interests you besides “people demonize ketamine”.
Look up the history of Thalidomide. There are plenty of examples of “this is a game changer” medical interventions which time proves to be harmful.
Just write about YOU and stay away from the medical lecture and it will be a fine essay!
Such a thoughtful and thought-provoking message. Thank you very much for taking the time to think through this with me. And the overboard blueberries - now that’s the stuff of a killer personal essay 
@gsssg here is your essay topic, in my opinion: how you a deep dive in whatever interests you, with examples . This is about you, not neuroscience…and it’s kind of fun, charming…
True story: in third grade I wrote a scathing review of the Magic Treehouse books. I found them unbearably predictable. But a real question: I have always done the deep, deep dive in my areas of interest over the years. I knew a ridiculous amount about deep sea creatures. I could give you the specs on every Italian supercar. I was intense with Magic the Gathering and could suss out an opponent’s strategy after the first couple plays and spot a card that would hold its trading value even before I played it. But those interests are well in the past - fond memories now. Isn’t that just stuff I’ve abandoned and that doesn’t show anything useful to the AOs? (I hate that I know that acronym).
Also there is a free essay reading here on CC if that would help. I think it helps to pretend you are sitting across from someone and talking about the topic. In other words, it is okay to write naturally, even conversationally.
You often give this advice, but I am not sure it is offers the direction students need. Whether a college essay should be “soul baring” is nuanced. So many solid essays are deeply personal, but also maintain appropriate boundaries.
I meant my comment as a general thought to keep in mind as the OP frames their essay. I did not say the OP should avoid writing about anything personal-- simply noting that the end goal of the essay (to gain admission to college) should always be kept in mind.
I have occasionally reminded students that the admissions folks are not therapists
Re-reading after the comments - and you say someone reacted negatively.
What do you have to do with MDMA or neuroactive compounds.
The essay is about you - not about the compounds.
So you are interested in researching brain disorders.
That’s great but you don’t need to define brain disorders or cures for them.
You do need to define how your interest here relates to you being an asset for the school and vice versa.
Or how it’s helped you grow as a person, researcher, etc.
You needn’t give findings - it’s not about solving these issues.
It’s about how your interest has developed you as a person and made you a good fit for their school.
I would write about it. Here’s a book in which the author traces its use back to ancient times:The Immortality Key, by Brian Muraresku. The author is a DC lawyer who was a Classics major at Brown.
Thank you! Ordered it.
Do that. You seem stuck. You also seem to not understand what this essay is about for college . Set this subject aside for a bit and try something else.
You don’t want to lecture to your reader or write above their knowledge base. Kinda boring. You got like 10 minutes for the whole application. That first paragraph has to bring in your reader.
You mentioned upthread about liking to go “Deeper”. I would want to learn about that. Colleges like students that like to challenge themselves. Tell me more. Colleges also like active participation on campus. How will you do this?
I like essays that are personal, unique and interesting. Talking about this and that medication for brain disorders is none of that. It might make for an interesting research paper once in college though.
You like brain disorders. Cool. Great opening line." I love learning about brain disorders". That might pique my interest. But how does this relate back to your major? How does it make you “Go deeper”. What will you do on campus? You don’t want to come across 100%only academic. That won’t impress anyone. Flag football is also something awesome to do on campus.
Good luck. .
Note :I didn’t read the rest of the thread but just did. You are getting good advice and I just repeated it without reading the above before. 
Posting this again for emphasis: I really enjoyed it.
True story: in third grade I wrote a scathing review of the Magic Treehouse books. I found them unbearably predictable. But a real question: I have always done the deep, deep dive in my areas of interest over the years. I knew a ridiculous amount about deep sea creatures. I could give you the specs on every Italian supercar. I was intense with Magic the Gathering and could suss out an opponent’s strategy after the first couple plays and spot a card that would hold its trading value even before I played it. But those interests are well in the past - fond memories now. Isn’t that just stuff I’ve abandoned and that doesn’t show anything useful to the AOs? (I hate that I know that acronym).
When my 3 kids were writing essays, I suggested they look at photos from childhood. One wrote about Legos, one about blueberry muffins, and one wrote about their childhood fascination with rubber erasers. With a twist at the end to relate it to college. They did well with admissions. I strongly suggest you use specific “fun” details as you did when writing to us. Maybe a survey of those times when you “dug deep” as a sort of review of your life. Your twist at the end could be that now, in college, you want to dig deep into neuroscience etc.
The backbone of your essay is in this thread, you’ve revealed how you think (your natural thought process looks two or three steps ahead from the onset which is why predictability bores you, you aren’t satisfied with surface skimming knowledge, you excel at games of strategy, you have a 360* perspective, etc) and I personally think it makes it easy to see how that makes you an asset to your interest area of neuroscience (especially research). The work now is in putting that together in 650 words and making it flow in a compelling way that piques their interest about you more than the neuroscience. I think your original post was heading in the direction of research paper and also at risk of sounding like lecturing the reader, as others have stated. For what its worth, “in third grade I wrote a scathing review of the Magic Treehouse books” has the makings of a great opening “hook.”
Seconding what everyone here has said. Don’t make it about your research interests - make it about you - your love of the unexpected, your delight in ambiguity, etc.
Btw, upthread you contemplated taking a stab at a different topic. Do it! Maybe even twice. Our school required every student to submit 2 personal essays just to test out ideas and themes. My kid ended up writing a completely different one (a 3rd or 4th), and it was great. But it took a few efforts for it to percolate. You may end up with bits and pieces from the first efforts that will help with supplemental essays, and in the end, you’ll have your arsenal of what you want to say about yourself that may not be in the rest of your application.
OP, I just want you to know that the problem here isn’t you, the problem is the screwy admissions process to America’s most selective colleges.
If you were applying to any of the top universities abroad, they would want you to write a straightforward essay about your proposed course of study and why you wished to study it. There would be no need to spin some nonsense about what you would bring to the flag football team, or why you love blueberry muffins, or a cute story about an essay you wrote when you were 8. In my opinion, it’s all just another hoop to jump through that allows them to justify selecting kids with paid college counselors who teach them the secret handshake to writing these dumb essays. In other words, rich connected students. Luckily for you, you’ve stumbled upon a free source of the secret handshake. Because the advice you have received above is correct, but you were not dumb not to have known it.
There is no secret way to write a college essay. If any counselor tells one that, they should run in the other direction.
In the big picture, relatively few schools care about the common app essay. Some don’t even read them, including uber selectives like Northwestern. Some have their own essays, which tend to focus more on why a certain major or other quite specific prompts, like the UC PIQs.
It looks like OP is applying to a bunch of the UCs so I would recommend they follow the very specific PIQ directions that the UCs publish. Some will also run virtual sessions to help guide the process. Again, there are no secrets.
Beyond giving OP the resources I already did, I didn’t post in this thread. Generally, I wouldn’t write about ECs. I also wouldn’t write about what one liked when they were a kid, unless it’s limited to a sentence or two and is directly applicable to who the student is today.
With that said, nearly anything can make a good common app essay. I think some students struggle with writing about themselves, which is understandable. They’ve been drilled in how to write in the five paragraph format which these essays definitely are not, and that’s immediately apparent if on reads the many free resources at reputable sites like the college essay guy, or the various college sites.
For OP, I would write a story that communicates who they are. As a person, friend, family member, student, anonymous poster online, whatever. Don’t overthink it. Keep it simple.