Serenity - Sorry, I'm a drug guy; I haven't even heard of PSP. As for antidepressants; those I know some things about.

Both Celexa™ (citalopram) and Zoloft™ (sertraline) are in a family of drugs called SSRIs (serotonin selective reuptake inhibitors) which help to relieve depression by boosting the brain's concentration of serotonin (a neurotransmitter that helps carry electrical signals from one nerve cell to another).

All medications have side effects. Side effects are just effects of the drug that we don't need to treat a certain condition. Sometimes side effects are advantageous; as when another SSRI, Paxil™ (paroxetine) blocks muscarinic receptors, which can lessen anxiety and help the drug treat panic disorders.

Citalopram is called the "cleanest" of the SSRIs in that it binds to and blocks the serotonin reuptake mechanism on the pre-synaptic surface in the synaptic gap, but has little affinity for other receptors. In other words, citalopram does what other SSRIs do, but not much else. Therefore, citalopram will have fewer side effects than other SSRIs, including Zoloft.

Here is a fairly comprehensive monograph of <A target="_blank" HREF=http://www.mentalhealth.com/drug/p30-c04.html>citalopram</A>

If you have anymore questions, please ask. - Cam