the truth of the matter is it's not only deeply wrong, but that they didn't have a damn clue when they invented them and have been bouncing around all kinds of theories ever since
of course, these are all lies
SSRIs take weeks to take effect, and have a long (weeks-long) withdrawal, even though their duration of action is far shorter than that.
they don't take weeks.
in fact, there are drugs that "give you serotonin" or otherwise agonize serotonin receptors! you probably know a few! LSD is one.
but it's yet more complex than that.
is that depression appears to involve *actual physical brain changes*, and treating it involves *actual physical brain changes*, and relates to BDNF (brain-derived neurotrophic factor)