What are the motifs in Requiem for a Dream: A Novel by Hubert Selby?

Escape is a recurring idea at every turn of the novel. The characters are running from everything in their lives; ducking and slipping away continuously. The subject of escaping never comes up in direct conversation but the wave passes through each character's life. Collectively they are all using their addictions and escaping to their dreams but from separate obstacles. With the diet pills Sara can escape her refrigerator taunting her to taste her favorite foods. Or she imagines herself on television at the center of everyone's attention in order to escape the loneliness that weighs on her life.