Sexual assault
Sexual assault is one of the most impactful themes in Crank. Unfortunately, sexual assault and addiction frequently go hand-in-hand. Those who are addicted to drugs or alcohol are frequently victims—or perpetrators—of sexual assault. That is true for Kristina, who is sexually assaulted on a number of occasions by various men in her life. Invariably, these men claimed to love her and cherish her. However, all they wanted from her was sex and a way to get more drugs. Being an addict breeds desperate, oftentimes awful behavior, which is exemplified by the sexual assaults Kristina experiences. These assaults damage her significantly both physically and mentally; they also result in her pregnancy, further complicating her already unsavory and unsatisfactory life.
Having a dual identity
After trying drugs for the first time, the novel's protagonist, Kristina, adopts a new persona, Bree, for when she is under the influence of methamphetamine. Bree is a completely different person than Kristina, who is an honors student. Bree is darker and more impulsive than Kristina; she also partakes in dangerous substances and behaviors. Kristina's dual identity is a metaphor for the way that people change—and change dramatically—when dealing with drug addiction. Through her dual identity, the novel shows how radically drugs can alter someone's personality, choices, and values. Will she be a good honors student? Or will she be a party animal and drug addict?
The destructive nature of addiction
Perhaps the most important theme in Crank is the destructive nature of addiction. As Kristina, the novel's protagonist and main character, becomes more entrenched in the drug world (particularly meth), she sacrifices her relationships, academic potential, and even her self-worth in search of a quick fix. She also personally deals with a number of difficult things, like sexual assault. Additionally, the novel shows how addiction not only impacts the drug user; it impacts their loved ones, too. Because of her drug addiction, Kristina's relationships with her family, especially her mother, are strained as they watch her spiral and have no control over it. Her addiction also leads to a series of poor choices, including unprotected sex, which results in the birth of her son, Hunter. Ultimately, the novel is a warning against using drugs.
