Hello Uncle_Sam: I see this is your first post here on PC. So... welcome to PsychCentral!
I don't know if you're simply here seeking advice with regard to this particular concern, or if you plan to hang in here with us.
However should you be planning to continue on (we hope you do) may I suggest you introduce yourself to the general membership over on our New Members Introductions forum? Here's a link:
https://forums.psychcentral.com/new-...introductions/
I'm sorry your classmate is having such a difficult time. It's wonderful that you care enough to come here seeking advice. Unfortunately, there are so many different possibilities here I doubt there's really much of anything we are going to be able to offer. (Perhaps there will be some other members who will have some suggestions they can share.) I see too that you're in Europe. This makes it doubly difficult for me since I have no idea what types of services are available where you live.
Perhaps the best thing that could happen for this girl would be for her to be able to see a counselor or mental health therapist of some sort so she would have someone she could talk with about all that is going on with her. Beyond that, I think about the best you can do would be to be available to listen should she want to talk informally with someone about what's going on with her.
I suppose it might also be possible that you could speak with a trusted teacher or other staff member at the school the two of you attend. However, since I don't know anything about your school, I obviously don't know if this would really be a good idea or not. If you were to think about doing this, though, you might want to tell your friend you're going to do it beforehand. Here again, since I know so little about your circumstances it's really difficult to offer much of anything in the way of advice.
Here are links to 4 articles, from PsychCentral's archives, on the subject of how to help a person who has ADHD (attention deficit hyperactivity disorder) or a mental illness. Perhaps some of the information in these articles, can be of some help:
https://psychcentral.com/lib/helping...ealth-concern/
https://blogs.psychcentral.com/livin...e-in-a-crisis/
https://psychcentral.com/lib/a-toolk...th-adhd/?all=1
https://blogs.psychcentral.com/careg...ental-illness/
My best wishes to you both.
