420 may not be medical, but I would call it clinical.
It is sent after the student has already been diagnosed by a medical professional and ticked the "yes" box, but IMO it is still beyond what we are qualified to do, which is to train, assess and examine students with reference to the Part 61 Manual of Standards, nothing else.
Occasionally as a CFI I have been asked to assess whether people over a certain BMI can safely enter, exit, do up seat belt and have full and free control movement, but those are things that are easily measurable and not subject to any bias