A recent study suggests that teenagers who have trouble sleeping may be at a higher risk for being depressed and using drugs later in life. In the study, teenagers who had symptoms of insomnia were 2.3 times more likely to develop depression in early adulthood than adolescents without symptoms of insomnia. The insomnia group also was more likely to use alcohol, marijuana, and other drugs. The study involved 4,494 adolescents between 12 and 18 initially, and 3,582 young adults between the ages...