Can early in a relationship cause depression in teens?

It can cause depression because you become emotionally dependant on that one person and teenagers are just not ready for that type of thing. Once that person leaves, you're still emotionally attached and they broke that trust so you become depressed. You should definately find a therapist to talk to and you may need anti-depressants... Once you've gotten therapy it might get better. Also, talk more to your boyfriend about how you feel. Good Luck! I hope you feel better.