For me, it was my junior year. Things were beginning to ramp up in terms of workloads, and I actually came down with a sickness that put me in the hospital and out of school for several months. When I came back, the staff refused to help me catch up, stay caught up or even help me study for tests. This was one thing I couldn't do alone, and after weeks of this I started to become depressed.
When a teacher caught me crying they claimed I was suicidal and unfit for the school, and they demanded I get psychological help or they would remove me from school. At this point, going to a private school, I could not afford both, and I did not need the treatment from step one. Everyone cries, right?
Anyway now I'm finishing up my high school career online.