Well, AD's do in fact do "something"... The unknown is what is scary IMO. However, people do react, and the reaction can be viewed from different perspectives. Many people report the "I don't give a ...." feeling after a decent amount treatment. Some people react very quickly, sometimes one of the first things to happen is a boost in energy, unfortunatly, this boost can cause "mania." That is why the suicide rate spikes after a week and a half or so, when you come down from your manic episode. Some people feel nothing, some anxiety, sleeplessness...etc.
The bottom line here is it does have an affect, the question that still baffles the medical profession, is why... and how? More is unknown than known.
One report doesn't justify an innefective drug, years of "seeing is believing" has shown that these medicines do work.(Or at least have some effect.)
Placebo's allways have an effect, but now we are talking "mind over matter." However, when looking for help, maybe "mind over matter" is exactly what many people need.