What is the leading cause of death in adolescence is?

The number one cause of death in teenagers is car or motorcycle wrecks, but alcohol and drugs are usually involved, so these things tend to be interconnected.

Trauma: alcohol-related car wrecks, homicide, suicide, drugs, drowning.

Mental health problems: depression, suicide, drug abuse, overdoses

HIV and other sexually transmitted diseases (often contracted while drunk or high)

Eating disorders like anorexia nervosa and bulimia (often related to low self-esteem, depression, and power struggles with parents.)