Adolescence describes the teenage years between 13 and 19 and can be considered the transitional stage from childhood to adulthood. However, the physical and psychological changes that occur in adolescence can start earlier, during the preteen or "tween" years (ages 9 through 12). Adolescence can be a time of both disorientation and discovery. The transitional period can bring up issues of independence and self-identity; many adolescents and their peers face tough choices regarding schoolwork, sexuality,drugs, alcohol, and social life. Peer groups, romantic interests and external appearance tend to naturally increase in importance for some time during a teen's journey toward adulthood.