The main problem found in Sarah Dessen's young adult book Dreamland is that protagonist 16-year-old Caitlin O'Koren feels she needs to find a way to separate her own identity from that of her sister's, to find herself.
Dessen's novel opens on the day that Caitlin turns 16 and her 18-year-old sister Cassandra, nicknamed Cass, runs away from home. Caitlin and Cass had been very close, and the loss is a severe blow to Caitlin. In fact, the two had been so close that Caitlin now feels she needs to find ways to be different from her sister. Caitlin's desires to be different leads to Caitlin agreeing to try out for the cheerleading squad with her best friend Rina, something Caitlin knows Cass never would have done. Caitlin's inauguration into the cheerleading squad and the popular crowd leads to Caitlin meeting Rogerson Biscoe, whom she starts dating because he is different and again someone Caitlin knows Cass never would have become involved with. However, sadly, Caitlin's involvement with Rogerson leads to her life spiraling out of control as she finds herself involved in drugs and the victim of abuse. Had Caitlin never felt the need to be different from her sister, she never would have become involved in these problems, showing us that it's her need to find herself that is the main problem in Dessen's book.
Other evidence of the main problem can be seen in allusions to T. S. Eliot's poem "The Love Song of J. Alfred Prufock." One of Caitlin's classmates explains that Eliot is "talking about his separateness from the rest of the world, the kind of dream-state he is in, all by himself. He says he's underwater" (p. 245). All throughout the novel, this is exactly how Caitlin felt--she felt like she was underwater and separated from the world all because she wanted to separate herself from her sister. The upside to the story, though, is that she did indeed find herself and her own story.
On Caitlin O'Koren's sixteenth birthday, her older sister Cass runs away to be with her boyfriend. Upon her departure, the main problem is that Caitlin feels lost and hopeless. She joins the cheerleading team to make her mother happy, even though she has no desire to do so. Most importantly, as a result of this hopelessness, Caitlin develops an abusive relationship with a drug dealer named Rogerson Biscoe. She convinces herself that she feels safe around him, although he physically beats her.