A big problem with the framing is that, if you look at the actual studies, what typically happens is that some patients improve significantly on the SSRI being

A big problem with the framing is that, if you look at the actual studies, what typically happens is that some patients improve significantly on the SSRI being studied, while most others don't get any real effect, not above placebo at least. What this should tell you is that SSRIs are almost always worth trying, because you might be one of the lucky ones for whom they work great - even if chances are they won't. Psychiatric treatment always works on this basis anyway - try one drug for a few weeks, see how well it does, then decide to either adjust dose, or try something else. Most patients eventually find something that works for them, though a the minority that don't is also large, unfortunately.