Teenage mood swings are a natural and normal stage in your teenagers life. Here are some warning signs and tips to deal with the mood swings in teenagers. Apr 27, - Symptoms of teenage depression include: Changes in mood, such as anger, irritability or sadness. Changes in behavior, such as sleeping or eating more or less than normal, using drugs or alcohol or withdrawing from friends or family. Feelings like loneliness, apathy or insecurity.