Hi ,I would leave. It sounds very abusive and should follow your gut. To thyne own self be true and the truth shall set you free. I suffer from depression and have never treated my husband like that. If I did he would leave. So as from my own expierence as a depressed person. I dont think its depression as much as just plan being mean. Dont expect it to stop, and dont allow it anymore. Maybe she needs to be on her own for a while and get a dose of reality. My opinion only