The main question is Why does they think that way?
one of the reason why is because teenager is still in the process to develop their own identity, thus it is easy for their emotion to being broken down. Thus make teenager needs a lots of attention in order to handle their own emotion. Transformation from a child to a teenager is not easy this days. lots of challenge would coming. As they passing through many changes either biological or mentally, teenager this days have to adapt with the new surrounding which is extremely dangerous for them if they can't manage themselves. It was understandable that they faces changes either in their emotion. However, they would have to look for some reliable person which they can trust. Teen nowadays seem feel afraid to sharing their problem with their parents. Hence, parents also need to playing their own role in explaining or comforting their children. If possible, don't trying to watching over them too heavy or they might feel blocked or annoyed with care that had been given to them. I don't saying that the secure by the parents is unnecessary, i think parents should take moderate view in watching their child. Usually, when a teen was being secured too much. They might think that their parents don't trust them. However, when the parents was giving too much trust to their children would become a problem too as the teenager might goes out of control. Therefore, the best way is to take moderate consideration on the child action.
Other than that, I think that the teenager would need to learn on how to deal with their personal matter. But as I mention before, the interference from their parents is crucial as they have to know their children very well. Duty of the parents not only on giving appropriate things for their child, it also giving them guidance so they would growing up in a right manner.
For teenager, the world is full with colors, don't see the world only in black and white. Seek for something that would make you happy and cherish. It was wonderful to have a color of life. But, remember to control what you had feel!