I see why you are writing in with your question. Your situation is a bit tricky because you violated your classmate's privacy by reading her journal without permission. But a suicide threat is definitely not something to ignore...

According to our consulting adolescent psychiatrist Dr. Frederyka Shabry, it's not unusual for teenagers to have passing thoughts about suicide. Sometimes writing those thoughts down can actually serve as a kind of release for the person. It's hard to know, in this case, whether the feelings have passed, but when dealing with a potential suicide, it's better to be safe than sorry.

Studies have shown that more than three-quarters of the people who have committed suicide had done something to communicate their pain to friends and relatives in the weeks or months prior to their deaths. You may never know whether your classmate leaving her journal around was a "cry for help", but now that you know about her situation, you're right to treat it seriously.

Please get help from a professional right away. Make an appointment with your school counselor and explain what you have discovered. She or he will know where to go from there.

If you aren't close to your classmate and/or can't deal with her personally, you can ask the school counselor not to mention your name. If you are friends with the classmate, and decide to admit looking in her journal, you might want to apologize for your actions, and let her know you're concerned about her. Encourage her to talk about what's going on, but avoid arguing, preaching or telling her how she should feel. Just showing her that you care and that you are willing to be there is likely to be a big help. Your counselor may be able to suggest other ways you can offer support.

Also take a look at excerpt on teenage suicide and suicide resources from our book DEAL WITH IT! A Whole New Approach to Your Body, Brain and Life as a gURL.

All the best to you and your classmate.