This is sort of a two-parter.
1) If a teacher thinks a student is depressed, do they have to tell the parents or any other teachers? If the student denies being depressed, but it's pretty obvious they are, does the teacher do anything else or just leave it be?
and
2) If a student tells a teacher they are depressed, what would the teacher do differently? In terms of telling people, keeping an eye on them, etc? And if a student told a teacher they were depressed, but hadn't told their parents, would the teacher be obliged to tell the parents?
And do the answers depend on the age of the student?