The difference between the classifications of “troubling” and “troubled” youth lies first in the meanings of these two words. “Troubled” refers to someone that is anxious or worried, disturbed somehow within himself or herself. Someone or something that is “troubling” is, on the other hand, a cause of anxiety, worry, or distress to others.
When we apply these words to young people, we can say, then, that troubled youth are those who are wracked with anxiety and internal difficulties. They are potentially a danger to themselves. Troubling youth, in contrast, are those who are a danger to the people around them and potentially to society. They are most likely troubling because they are troubled, but in their troubled state, they act out toward others.
Let's look at a couple examples. A teenager comes from a broken home that has never given her much security. She has retreated into herself and has started drinking because she thinks it will ease the pain of what she feels as rejection from her parents. She is quiet at school and never gives the teachers any trouble. Mostly she just keeps to herself. Her grades, however, are slipping, and she is clearly unhappy. This is a troubled teen. She is anxious and disturbed within herself.
Another teenager also comes from a broken home. He, too, feels like he has no security in his life, no one he can rely on for support and help. This teen is also anxious and scared, but he is angry, too, and he starts acting out. He gets into fights, vandalizes a neighborhood playground, threatens his teachers and classmates, and generally creates havoc for nearly everyone he meets. This is a troubling teen. He is troubled as well, feeling internal distress, but he acts out his distress in ways that negatively affect others.