Can you call the police on someone who is severely mentally abusive?

No, the police can't do anything if someone's hurting you only with words. If that were the case, they'd be in everyone's house at one time or another. If it's between 2 adults (you being the one getting mentally abused) you just need to leave or get him/her to counseling. That's the U.S.' take on it but I'm sure Canada is the same.

What you can do is call the police discreetly and tell them you have a man or women going nuts and needs an evaluation . Happened to a friend of mine and he got his stepmother evaluated and shes now on medication and has stopped the harassment . You should do it or seriously leave because its going to add up until you can't take it anymore and snap .

Edit - Mental torture is worse then physical because it can make a man or women do things they wouldn't normally do under any circumstances , I do believe there should be a law for this reason but anyway please if it is you or someone else , take my advise .

I don't know Canadian laws but I'd tend to think no. That is something very hard to prove. What abusive to you may not be abusive to another. However, mental health counseling might help you or them. If its your parent maybe child protection can help.

I don't know Canadian laws, but I suspect not. However, there's nothing to stop you from leaving that person. Find a good domestic violence support group, find your options (I'm sure there are more than you realize), and get a way from him/her. Good luck