Well you did a much better job describing how you define retrospective vs. prospective trial design. I still think the way you are defining it is not accurate, since retrospective trial designs have nothing to do with self-selection. That is a separate matter. All retrospective means is "looks back in time" at data that has already been collected.

However, you argument stills doesn't hold much water. How can a psychiatric drug be used retrospectively unless it has already been approved for use? If you're complaining about trial data on off-label use, then I won't argue, but the FDA does not accept retrospective trials to support drug approval.