what makes different ssri's have different effects?

[tundradesert523]

Just curious what makes the different SSRIs act differently. What makes zoloft different than prozac?

and can these chemical differences make a therapeutic difference? If my anxiety doesnt respond to zoloft is there a chance it'll respond to another ssri?

 

[MichelJacques]

Each of the SSRIs has a unique pharmacological profile, ie they act on various receptors with varying affinities. All of them have their main interaction with the serotonin transporter (SERT), but then they also interact weakly with other receptors (I believe sertraline interacts with the dopamine transporter for instance). The various SSRIs' receptor interactions cause further varied downstream effects (such as fluoxetine indirectly increasing dopamine and norepinephrine in the prefrontal cortex). Further levels of complexity are found in every person have different brain chemistry.

In short: no, if one SSRI doesn't give you the therapeutic effect you're looking for, that does not guarantee that others will also not.