[mikefivedeuce]

The studies can also take advantage of mean reversion and test patients that are experiencing uncommonly high levels of depression (eg, unresponsive to medication). Over time patients return to their usual level of depression (or whatever's being tested) and the treatment is deemed effective.

[niketear]

No, it cannot, the design is a a randomized controlled trial, the controls would also go back, what is measured is the difference.