Since Paxil and Zoloft are both SSRIs, the key word is "selective" - these meds target different neurotransmittor sites to inhibit the re-uptake of serotonin.
Individual differences in metabolism, genetics, nature of symptoms, other meds in the patient's regimen are among the variables used by a seasoned psychopharamcologist (psychiatrist specializing in psychotropic meds). Therefore, it's often trial and error until one finds the med that works - since one starts SSRIs at low doseages and work up to the point where it makes a difference.

Whatever helps "lift the cloud" and makes you function better is the one that is best

sigmund22