This question may be seen as an extension of my previous question, here. I was talking to a person online where s/he mentioned that psychiatrists themselves don't have an idea as to how SSRIs work. Upon searching YouTube, I found this video where the narrator goes on to make many statements referencing various journals, doctors, researchers, etc.
Here are some points in particular that have been bothering me a bit from the video;
[...] in 1965 he said that "some, if not all depressions are associated with an absolute or relative deficiency of catecholamines, particularly norepinephrine." After that researchers quickly turned much of their attention to serotonin, guessing a deficiency in serotonin to be a root cause of depression. So, in this case, researchers first understood how a drug worked, then assumed the cause of depression based on the way the drug works. [...] The American Psychiatric Association's own 1999 textbook explains that assuming depression is caused by low serotonin because a drug that seems to prevent depression raises serotonin "...is similar to concluding that because aspirin causes gastrointestinal bleeding, headaches are caused by too much blood loss and the therapeutic action of aspirin in headaches involves blood loss. So, in 1999 the APA is making fun of how the chemical imbalance idea came to be.
Going back to antidepressants again, we’d want to know the context in which you introduce this medication. A genetic test, for example, would be helpful, but before you introduce a drug that increases serotonin signalling, we would at least want to verify that the person actually has low serotonin levels. Especially because antidepressants are known to have a very high risk for complications including the potentially life-threatening serotonin syndrome and a black box warning for “suicidal thoughts and behaviours.”. But as researchers at McMaster University explain, “It is currently impossible to measure exactly how the [living] brain is releasing and using serotonin..." [...] In 1971, investigators at McGill University failed to find a “statistically significant” difference between the 5-HIAA levels of depressed patients and normal controls and there was no correlation whatsoever between depression severity and levels of 5-HIAA. Then in 1974, two researchers at the University of Pennsylvania found that a serotonin depleting drug didn’t reliably induce depression at all. Then, in 1975, investigators at the Karolinska Institute in Stockholm found that 30% of the depressed patients they tested indeed suffered from low levels of the serotonin metabolite 5-HIAA. But, they also found that 25% of the “normal” group also had low cerebrospinal levels of these metabolites. Finally, in 1984, NIMH investigators wanted to see whether those depressed patients with low serotonin would be the best responders to an antidepressant. Unfortunately for the chemical imbalance theory, lead investigator James Maas wrote, “contrary to expectations, no relationships between cerebrospinal 5-HIAA and response to [the antidepressant] amitriptyline were found.” Simply put, researchers assumed that antidepressants were working their magic in a certain context based on what the antidepressant does, not based on proper evidence for that context.
[...] Have a listen to Psychiatrist Daniel Carlat’s comment on this: "But on the other hand, what we don't is we don't know how the medications actually work in the brain... when patients ask me about these medications, I'll often say something like, well, the way Zoloft works is it increases the levels of serotonin in your brain... and presumably the reason you're depressed or anxious is that you have some sort of deficiency. ... I say that because patients ... certainly don't want to hear that a psychiatrist essentially has no idea how these medications work." So with antidepressants, we don’t actually know why they would work, and there’s doubt about whether they actually do work. [...] But what happens in people who just don’t take medication? In Robert Whitaker’s book “Anatomy of an Epidemic,” he explains that before the age of antidepressants, people’s depression would usually resolve by itself eventually. A 1931 long term study of 2,700 depressed patients reported that more than half of those admitted for depression only had one depressive episode and no relapse. [...] At the end of 6 years, the people who received the medication were more than 3 times as likely to have stopped functioning in their usual societal roles.
And there are many points he said in the video (that I didn't quote so as to not make the post long enough to read, but keep it succinct as well) that I am totally unable to accept as hardcore facts/pieces of evidence against anti-depressants and that doctors, as well as researchers, don't know what they are doing. This is totally against what I have seen here and here. The video craftily puts a disclaimer before that if someone is on medication, they should first take the advice of their physician/psychiatrist, but goes on to plant the seeds of doubt. And as I am a novice in this field, this video has managed to boggle my mind as well has irked me a bit. I'd really appreciate it if I get some clear explanations as to what is going on here. Regards!