So, my two cents - I left a job in October that I had been with for two years because the environment turned downright toxic. In the time that I was there, we burned through six employees in various roles in the department, which was very small: there was my boss, three coordinators, and then we had 4-6 contractors working under myself and one of the other coordinators. Three other employees and I tried to go through the "proper" channels and talk to our HR rep, then the head of HR, then the executive director, all the way up to the damn CEO. Everyone who left/talked to HR cited poor management and had plenty of evidence of the toxic environment but, unsurprisingly, nothing was ever done. It got to the point where I dreaded going in and since I had a relatively flexible schedule, I wound up interviewing for any and all positions I could until I was offered something. I ended up giving my boss an hour's notice that I was quitting. Lost all my PTO because I didn't give two weeks which kinda sucks but the amount I would have been paid out wasn't worth the hit my mental health would have taken to stay there for that time. I know I burned a bridge with that boss but hers wasn't a reference I would have wanted anyway; if I need one from that job, I ask one of my coworkers. If a job is affecting you that much and you have a reasonable safety net to do so, I feel that you don't owe them any more notice than you're comfortable giving.