I have been friends with this person for quite a few years. In the time I've known them they have significantly increased their drinking. They say it's a way for them to cope with their depression. Around once a month they tell me they are suicidal. This is usually when they are extremely drunk.
If I don't respond in a way they think suitable they become abusive. I will say things like have you thought about professional help/ how about trying to cut down a little as alcohol is a depressant etc. Nothing controversial and I'm always caring. I've found when I spend time with them I drink more too but I don't want this to continue. I really love my friend but for want if a better phrase I feel dragged down.
I have tried really hard to help, offered to attend any appointments to help improve their mental health but once sober they dismiss there is an issue.
They also have no issue finding fault with me but if the situation was reversed they would literally go ballistic. Another issue I have is I work with this person and they are senior to me. It feels like what used to be a fun friendship has got dark pretty quickly.
Any advice would be appreciated.