[raducu]

I don't understand the part about " an antagonist and a suppressant".

Do you mean agonist-antagonist mechanism of action of some drugs that treat the same condition?

As far as I know different drugs can work on serotonin/dopamine/norepinephrine but in different parts of the brain and produce different results.

[ggm]

I am a layman so probably use words inadvisably. Some drugs supress effects in the brain, some enhance. Yet both are seen to be deployed to try and treat depression. This is a very confusing signal. If the condition can present from either too much or not enough of something, what diagnostic determines which to try? What evidence do we have, of a mechanism to determine which except for "suck it and see"

[raducu]

I see, my intuition is that the brain is like a very complex analog amplifying station with different types of transistors, capacitors, resistors, whatever.

Drug A decreases 100ohm resistor values to 50 in a noise filter stage and "fixes" your problem with the radio.

Drug B has same 100ohm -> 50ohm effect, but in a different section of the radio and doesn't work.

Drug C increases the speaker resistance from 5ohm -> 10ohm and "fixes" your problem because you simply cannot hear the noise.

Drug D increases the microphone resistance from 5ohm -> 10ohm and the noise simply is not picked up.

Drugs A and B work the same way, drug C and D work the same way, but opposite to how drugs A and B work and they all provide the same net effect as far as I'm concerned.

[ac29]

This is a good analogy, because there are a lot of different biochemical pathways that can play roles in mental health. To add add to that, here's a good image of 4 of the ways a drug can effect activity at certain sites (not mental health specific, general pharmacology principles): https://commons.wikimedia.org/wiki/File:Inverse_agonist_3.sv...