by Christopher S. Wren

About the author: Christopher S. Wren is a staff writer for the New York Times daily newspaper.

Nicole, a high school junior with short brown hair, soft eyes and a delicate chin, has smoked marijuana since she was 13 years old. Many of her friends at her Massachusetts high school use it too, and sometimes her father joins her.

“I smoke weed with my dad,” Nicole, who is now 16, said. “Obviously he feels fine about it. Since I started smoking weed, we’ve gotten closer.”

Marijuana has become so routine that Nicole admitted, “I smoke every single day.”

Marijuana Use: More than Doubled

The rising use of illegal drugs by teen-agers like Nicole was confirmed in August 1996 by the Department of Health and Human Services, which...