One is a normal response to something sad or traumatic in your life that may go away after a period of time without any treatment. The other kind of depression comes from a chemical imbalance and is considered a medical problem. You need to tell your doctor about your symptoms, how long they have been going on and what if anything happened that may have triggered your depression. If your doctor gives you a clean bill of health, meaning there are no physical causes for your depressive symptoms, ask him or her to suggest what you should do next. Your doctor may recommend a trial of medication, or suggest that you find a counselor or minister to talk with.
Many medical doctors think depression is just part of being a teenager .
If your doctor says you are healthy, but does not address the depression I would suggest that you find a local therapist to talk with or see the school social worker or guidance counselor. Any of those people could help you with your problem. You do not have to live with depression . . . Check out my response to another teen who needed to find someone locally to help with her problems but did not want her parents involved. Whatever you do .