What are the motifs in Crank by Ellen Hopkins?

The way things appear is a very important idea in this novel, especially in the relationship between Kristina and her mother. The importance of appearances becomes apparent when Kristina meets Brendan, and then again when she meets Chase. Brendan is a lifeguard. He is tall, muscular and attractive. Kristina allows her mother to meet Brendan because she knows her mother will approve of Brendan based only on appearances. Brendan's personality, however, is not nearly as attractive as his body. He rapes Kristina, leaving bruises on her body, then is hateful to Kristina and belittles her. Although he charges Kristina for the full price of the crank he finds for her, it is obvious that he has stolen some of the drugs before he gives the bindle to Kristina.