When my department manager came to our store, it was already a known fact to some of the employees that she had a prior drug addiction. There is plenty of stuff on the internet that talks about all of her past drug problems and legal issues. But it appeared as though she had gotten herself cleaned up and was able to get a fresh start. However, it has become obvious that her drug addiction has returned, and over the past several months it has gotten noticeably worse. For example, she has lost so much weight that she is starting to look like a skeleton, her eyes are glazed over quite a bit, her teeth are starting to rot, her hands are almost always trembling, sometimes she speaks with a rapid and jittery voice, her mood swings have become absolutely unbearable, she is missing more and more days of work, and when she does come to work she usually arrives late and leaves early. I didn't notice the symptoms at first, but a few of the other employees were able to spot the signs right away because they have been around drug addicts before. As the months went by I started to notice all of the symptoms too, and now it has gotten to the point that even some of our customers have been asking if she has a drug problem because it is becoming more and more obvious. And her ability to run the department has gone from being bad to inexcusable. Her symptoms are especially noticeable after she gets back from her days off. 

So far there has only been one employee that had the courage to confront her about her drug use, and offered to give her help if she would accept it. Needless to say, the conversation didn't go over well, and she totally freaked out. That employee has since left for another job, and now no other employees are willing to say anything because they are too scared about the backlash that they might receive for speaking up. I have had various problems with other managers in the past, and I discovered that if I report things to upper management, not only does it not do any good, but usually it just backfires when the manager finds out that you reported them. I've thought about writing anonymous letters to upper management, but I'm pretty sure that they would eventually figure out that I was the one who sent it, because I am usually the most vocal about reporting problems. 

I know that our store manager has been wanting to replace her for a long time, but apparently they can't find any qualified managers that are willing to work at our location, so it appears that we are stuck with her until something drastic happens. I'm not sure if our store manager or co-managers are aware of her drug problem, but it seems like they should have picked up on it by now. So I'm not sure what to do. I would hate to have to look for another job, because I have always enjoyed the one that I have, but her drug problem has caused her extreme moods swings to become absolutely unbearable to work with, and I just can't take it anymore. Does anybody have any suggestions on what I should do?