There are multiple serotonin receptor types, and the "selective" types of reuptake modifiers don't affect all of them all the time in all people.
That said, too much or too little serotonin absorbed by a specific set or another can have wildly different effects.
Too much serotonin is not a good thing. So you need to balance it. For some people, this means SSRIs, for some it means SSREs. That's the explanation for the imbalance model, and it does make sense given the science.
It's ridiculous to talk about "balance" when you can't actually measure any of the quantities you're trying to balance and don't even have a clear picture of what "balance" looks like qualitatively, never mind quantitatively.
Sure, blast a brain with drugs that aren't well understood and it'll behave differently, maybe "better" than before, relatively speaking-- but that's not a scientific model so much as a pragmatic clinical solution.
It's ridiculous to talk about "balancing" the flavors of your soup when you can't actually measure any of the quantities you're trying to balance and don't even have a clear picture of what "balance" looks like qualitatively, never mind quantitatively.
Sure, dump in a bunch of spices that aren't measured and it'll taste different, maybe "better" than before, relatively speaking--but that's not a scientific model so much as a pragmatic cooking solution.
It's obvious you don't know very much about serotonin. Here's why:
SSRIs bind to the serotonin transporter SERT. The 'selective' part means that it has a much higher affinity for SERT than other monoamine transporters (e.g., DAT or NET). Although you're correct that there are various serotonin receptor subtypes, there is only one known SERT (there is only one gene).
SSRIs do exhibit extremely weak affinity to serotonin receptors but it is so low that it doesn't matter which subtype has a higher affinity than another. If you want to latch on to 5HT receptors with interesting ratios and affinities, the correct psychiatric drug would be an antipsychotic.
Please stop defending the chemical imbalance model when you do not understand the science at all. Thank you.
That said, too much or too little serotonin absorbed by a specific set or another can have wildly different effects.
Too much serotonin is not a good thing. So you need to balance it. For some people, this means SSRIs, for some it means SSREs. That's the explanation for the imbalance model, and it does make sense given the science.