Maté describes the mandala, also known by Buddhists as the wheel of life. The mandala has six wheels, representing six realms. The hungry ghost realm contains addicts, and those driven by appetites. Maté describes the lives of most people as vacillating between realms.

Maté works with addicts in Vancouver, in a neighborhood he calls the Downtown Eastside. He sees the people society calls junkies as hungry ghosts. His intent with In the Realm of Hungry Ghosts is to show that their stories have worth. By telling their stories, he can also illuminate the processes by which people become addicts, and how society comes to shun them.