Marling - Sorry to disagree, but Prozac, Paxil, Zoloft, and Effexor are all SSRIs, not tri-cyclics. They're all different formulations, but all have the effect of slowing down or blocking the re-uptake of Serotonin, thus leaving more of the neurotransmitter available for use. I believe some of them have a slight blocking effect on other neurotransmitters such as dopamine - there are slight variations between the drugs. The best source of information on this would be your local pharmacist. Margie Swindler [log in to unmask]