Sadness and depression are linked but they are not the same thing.
Sadness is an emotion everyone experiences during their lifetime. There are many different life experiences that can cause a person sadness. The loss of a loved one, disappointment, peer problems, academic struggles, and other difficult situations can cause us to feel sad. Sadness is an emotion that typically gets better as time goes by. In the case of loss, it may resurface when you think of that person many years later. However, your ability to function returns to normal and other emotions are felt regularly.
Talking about the situation making you sad may help you feel better more quickly. Having a good cry, venting in a journal, or speaking with a trusted individual about how you're feeling are all ways to work through your emotions.
Depression is a mental disorder that affects many parts of a person's life. Depression doesn't usually go away by itself and lasts more than two weeks. If you feel you are depressed you should seek help from a doctor. Please let your parent or guardian know if you think you're suffering from depression.