What should be used for baselines against which to compare treatments' effectiveness?

None of the kinds of control groups that are commonly relied on in randomized clinical trials can provide a clinically ethical and meaningful lower baseline against which to demonstrate that any specific form of psychotherapy is worth providing. The outcome of the natural course of a malady is what logically sets the lower bound baseline for how effective a treatment for the malady ought to be, but natural courses of psychological maladies are now generally neither ethically nor feasibly determinable. So it is the available ethically adequate treatments for a psychological malady that properly must define a lower baseline against which to compare new treatments for their effectiveness. Optimal mental health is the obvious upper bound baseline, and so treatments ought to always be also evaluated against it to show how ineffective they are.