Rainz, you are probably too young to be manic depressive. I wouldn't worry about the diagnosis, but if you want to describe your symptoms and problems and why you are depressed, we may be able to she some light on that.
It's often difficult for a teenager to be diagnosed with Bipolar Disorder (older term is "manic depression") but not impossible. I'm Bipolar, my husband is Bipolar and my 15 year old son (in a few more weeks he'll be 16) from a previous marriage is Bipolar, too.
Teens are generally moody because they their hormones are changing rapidly as their bodies are being prepared for adulthood. If a teen is experiencing wild mood swings...euphoria, deep depression, grandoise thinking, extreme risk taking, uncontrollable non-stop talking, delusional thoughts, an extremely irritable mood, little or no sleep....etc. and drug or alcohol abuse isn't a possibility, then it's time to talk to a psychiatrist so he/she can investigate the possibility of Bipolar Disorder.
My son showed signs of being 'different' since he was first born. He was moody, cried a lot, very emotional, suicidal starting at about the age of 5 and exhibited other irrational behavior as he got older. When he was 14, he started having rapid mood swings. For weeks at a time he would become delusional and think that he was immortal and could take a bullet to the heart and live, stand in front of a car going 100 mph and live, etc. He thought he had great powers and went with very little sleep. Then he'd cycle into a deep depression for a couple of weeks...He wasn't on drugs or drinking alcohol. We took him to a psychiatrist who diagnosed him with Bipolar Disorder, and he has since started seeing a different psychiatrist who has also confirmed the diagnosis of Bipolar. He is being sucessfully treated with medication and he is doing extremely well.
I think that you should talk to your parents/guardians about the problems that you are having. Ask them to please take you to a psychiatrist to be evaluated. I don't know where you have heard about Bipolar Disorder, but if you are concerned about it, then you should get some help with it to see if you are, or to help you understand that what you are experiencing is normal for a child your age. You need peace of mind either way.
You're welcome to visit our website: "A Silver Lining" to learn more about it and talk with others there who might be able to help you more.
Good luck to you honey!