If nobody does nothing about it, it will eventually blow up, but probably not in the nicest way.

I had a similar experience with a professor that had a more than a small problem with alcohol. We were students, so we didn't want to risk our mark/course by going "against" him/her, so what we did was (as ff524 suggested) to write some anonymous letters to the department. This lead to him/her going to seek help and everything got fixed in the end.

If nobody would had done this, probably it would have ended in some very unpleasant situation where probably the school would have been forced to fire him/her. Informing the school about the problem was definitely the best option for students, the school and him/herself.

This is just a personal experience in a bit different scenario, but I thought I may be helpful.

If nobody does anything about it, it will eventually blow up, but probably not in the nicest way.

I had a similar experience with a professor that had a more than a small problem with alcohol. We were students, so we didn't want to risk our mark/course by going "against" him/her, so what we did was (as @ff524 suggested) to write some anonymous letters to the department. This lead to him/her going to seek help and everything got fixed in the end.

If nobody would had done this, it would probably have ended in some very unpleasant situation where the school probably would have been forced to fire him/her. Informing the school about the problem was definitely the best option for students, the school and him/herself.

This is just a personal experience in a bit different scenario, but I thought I may be helpful.