Oct. 8, 2005 -- When Erin Polk first got to college, everything was great, until …
"Second semester hit, depression hit," Polk said. "I was hopeless, like, completely hopeless."
A student at Mary Washington University in Fredericksburg, Va., societal and academic pressures filled her with despair.
"I could see college students laugh down the hall," Polk said. "And I couldn't laugh with them."
According to a recent survey by the American College Health Association, 15 percent of college students were formally diagnosed with depression last year, up from 10 percent four years ago.
Doctors say one reason is medication. More young people with mental health problems are able to attend college.
Michelle and Fred Goodstein thought their son, Jonathan, was happy as a junior at the University of Arizona.
"We had no warning, no history, no anything," Michelle Goodstein said.
Then, one day, Jonathan shot himself to death.
"The thought keeps going: 'What were you thinking? What was going on with you that you couldn't share it?' " Michelle said. "Well, that's another thing that we'll never know."
There are 1,100 suicides on college campuses each year.
"There's been a dramatic increase in the amount of serious mental health problems on campuses across the country," said Dr. Richard Kadison of Harvard University.
Kadison said there are warning signs of depression that parents and peers should look out for, including sleep problems, social withdrawal and loss of motivation.
After receiving the proper medical care, Erin Polk is now doing fine. This spring, she will graduate with a degree in psychology and plans to start work as a school counselor.
"My goal is for students not to feel alone when they go through this process and to know how to get help," she said.
The federal government has also recognized the importance of the issue, recently announcing grants of almost $10 million to support suicide prevention among young people.
ABC News' Gigi Stone originally reported this story for "World News Tonight" on Oct. 2, 2005.