Problems exist in both United States' adolescents and other countries. But the magnitude of the problem may vary, (even more so if compared to third world countries).
In United States, problems in adolescents life revolve around maintaining high social status (popularity among peers) and focused on getting into higher education (for the poor it may involve obtaining part-time jobs)
In third world countries on the other hand, adolescents might as well become the backbone of their families because they barely have enough food to survive in their society.