I'm a 15 year old girl and I think I may have depression. My friends keep asking me if somethings wrong because I never contribute to conversations like I used to. I've lost a lot of weight, and I'm not interested in anything anymore. During school when we're taking notes or doing an assignment I find its hard to concentrate on anything. Sometimes I'll just start crying for no reason, not because of sadness, anger, or frustration, I just start crying. My friends will invite me over to parties, but i always make up an excuse just so I wont have to be around people. But the weird thing is, I've never felt suicidal, I mean I've though about death, and wondered what it would he like to kill myself, but I've never actually considered it. Is this depression?