Even if the brain is not apart from the rest of the body, there is a special thing between the two: the blood-brain barrier, which is actually quite hard to cross with medications, and poses a real challange in curing brain diseases.
Sure but the list of drugs that cross that barrier is long. Everything from antibiotics to statins.
And even if they didn’t, the body is a tightly interconnected system. Taking an antidepressant to “selectively affect serotonin” in the brain? Whoops, turns out your gut has at least as many serotonin receptors as the brain. Taking a statin to reduce cholesterol (which it does very well but with an NNT > 200 for heart attacks and NNT > 300 for stroke)? Whoops, it causes transient global amnesia and personality changes and diabetes in a lot of people. And 40% of the US Adult population we’re on statins in the mid 2000s.
I believe you, but I just wanted to read up about where serotonin receptors are expressed in the human body in what amount, but the Wikipedia page on serotonin receptors didn't write about it.
I'm not in the medical field, but try to keep up just a little bit to have some basic knowledge, but it's quite hard as often I see that Wikipedia is many years behind.
At the same time medical articles take a lot of time to read, as they are much less accessable.
It seemed like the reduced cholesterol was what impacted personality. I don't know if statins cross the blood brain barrier but if cholesterol levels themselves drive behavior changes it doesn't seem like they would need to in order to have an impact. This was the most interesting take away for me because it means that crossing the barrier isn't always necessary as indirect effects can be powerful as well.