Everyone feels down or blue once in awhile. Especially during difficult times, it's normal to feel sad or discouraged. But when those feelings persist for two weeks or longer, it could be depression. It's a common illness that affects an estimated 19 million Americans-that's nearly one in ten! It's also one of the most under-diagnosed illnesses on college campuses. The symptoms can come on so slowly that one day, a person realizes that he can't remember the last time he felt good. Here are some warning signs for depression:

Persistent sad, anxious, or empty mood
Feelings of hopelessness, pessimism
Feelings of guilt, worthlessness, helplessness
Loss of interest or enjoyment in things that used to be fun
Decreased energy, fatigue
Restlessness, irritability
Difficulty concentrating, remembering, or making decisions
Trouble sleeping, or oversleeping
Appetite or weight changes
Thoughts of suicide

Many students suffer needlessly. Depression is often very treatable. Not everyone experiences every symptom, and the severity can vary over time. Depression is not something you can just "snap out of" and make better on your own. This assumption can reinforce feelings of hopelessness and failure. It's important to seek outside help. Through counseling and, in some cases, medication, the majority of people notice significant improvement! If you are experiencing any of the symptoms listed above for two weeks or longer, here's what you need to do today: Make an appointment with a counselor on campus. Your counselor can screen you for depression and get you the immediate help you need. Do not spend another day suffering in silence!

To learn more about depression, take the National Mental Health Association's online depression screening at www.depression-screening.org.

To learn more about suicide prevention, visit the Jed Foundation Web site at http://www.jedfoundation.org/index.php.

For help with someone who is threatening to commit suicide, call 911 or the National Suicide Prevention Lifeline at 1-800-273-TALK. Their Web site is http://www.suicidepreventionlifeline.org/.

Susan Fee is a licensed counselor and author of the college survival guide, "My Roommate Is Driving Me Crazy! Solve Conflicts, Set Boundaries, and Survive the College Roommate from Hell" (Adams Media). She offers more college survival tips on her Web site, http://www.myroommateisdrivingmecrazy.com