The major themes of Ellen Hopkins' "Crank" include coming of age while struggling with addiction and facing the consequences of choices. According the Ellen Hopkins' website, the story is loosely based on her own daughter's struggles with crystal meth addiction.
According to Ellen Hopkins, "Crank" depicts a "good girl's" fall from grace. It follows the summer before and the time during the main character's junior year of high school. Kristina, the main character, starts out as a straight-A honor roll student. During a visit with her father, she becomes addicted to crystal meth, or crank.
The majority of the story talks about the decisions, mostly bad, that Kristina makes during this time period. Most bad decisions are followed by negative consequences that Kristina must face. For example, she becomes overly friendly with a young man who promises her more crank. She agrees to go into the woods alone with him. He then rapes her after they get high together. Kristina spends a lot of the rest of the story confronting the consequences of that afternoon.
"Crank" also explores the theme of coming of age, which is complicated by addiction. Kristina steals and eventually becomes a drug dealer. She attempts to keep up with school, but her grades drop drastically because she misses so many classes. Her relationship with her mother also becomes strained. These actions show the conflict associated with adolescence, magnified by the drug use.