Crank by Ellen Hopkins

In Crank, Ellen Hopkins chronicles the turbulent and often disturbing relationship between Kristina, a character based on her own daughter, and the "monster," the highly addictive drug crystal meth, or "crank." Kristina is introduced to the drug while visiting her largely absent and ne'er-do-well father. While under the influence of the monster, Kristina discovers her sexy alter-ego, Bree: "there is no perfect daughter, / no gifted high school junior, / no Kristina Georgia Snow. / There is only Bree." Bree will do all the things good girl Kristina won't, including attracting the attention of dangerous boys who can provide her with a steady flow of crank.