Adolescence is the transitional stage from childhood to adulthood that occurs between ages 13 and 19. But the physical and psychological changes that take place in adolescence often start earlier, during the preteen or "tween" years: ages 9 and 12.
Adolescence can be a time of both disorientation and discovery. The transitional period can raise questions of independence and identity; as adolescents cultivate their sense of self, they may face difficult choices about academics, friendship, sexuality, gender identity, drugs, and alcohol.
Most teens have a relatively egocentric perspective on life; a state of mind that usually abates with age. They often focus on themselves and believe that everyone else—from a best friend to a distant crush—is focused on them too. They may grapple with insecurities and feelings of being judged. Relationships with family members often take a backseat to peer groups, romantic interests, and appearance, which teens perceive as increasingly important during this time.
The transition can naturally lead to anxiety about physical development, evolving relationship with others and one's place in the larger world. Mild anxiety and other challenges are typical, but serious mental health conditions also emerge during adolescence. Addressing a disorder early on can help ensure the best possible outcome.