> My point that I failed to explain is that falsifiability is a much more abstract notion than testability in the empirical world.
Not in science. In science, falsifiability means the failure of an empirical test, a failure that invalidates a claim.
http://en.wikipedia.org/wiki/Falsifiability
Quote: "The concern with falsifiability gained attention by way of philosopher of science Karl Popper's scientific epistemology "falsificationism". Popper stresses the problem of demarcation—distinguishing the scientific from the unscientific—and makes falsifiability the demarcation criterion, such that what is unfalsifiable is classified as unscientific, and the practice of declaring an unfalsifiable theory to be scientifically true is pseudoscience. This is often epitomized in Wolfgang Pauli famously saying, of an argument that fails to be scientific because it cannot be falsified by experiment, "it is not only not right, it is not even wrong!"" [emphasis added]
> At its essence, a theory is falsifiable if it is possible to come up with an argument that proves the theory to be false.
No, falsifiability in science means that an empirical test -- a test against reality -- proves a claim to be false. In science, falsifiability is not about philosophy or rhetoric, it is about empirical tests.
> When it comes to treatments of all kind, all of them are falsifiable, as long as the treatment involves the promise of effects that we can observe either now or in the future.
In psychology, defined as study of the mind, none of those are falsifiable in a scientific sense, because the mind is not a source of empirical evidence.
> The problem with many psychological treatments ... [etc.]
Your paragraph explains why psychology is not and cannot be scientific.
> Bottom line is that us being unable to measure the effectiveness of a treatment, doesn't make that treatment unfalsifiable.
On the contrary, that is exactly what it means. No objective empirical evidence on which similarly equipped observers can agree, ergo no falsifiability, ergo no science.
In any case, falsifiability is only one missing property in psychology. Another is psychology's tendency to be satisfied to describe what it should be explaining. Are testable, empirical explanations required for science, or are descriptions adequate? To find out, read my description of a phony cure for the common cold posted above. It shows that explanations are a requirement for science, and to avoid all sorts of quackery.