Chronic pain and depression arise from faulty neural circuitry. "In both disorders, pain continues long after some initial insult has healed, disappeared or moved on, and the experience of social rejection or physical pain persists, feeds on itself and becomes chronic. Both disorders often seem mysterious in that their origins are hard to pinpoint. And both signal their presence with a subtle but powerful physiological marker: systemic inflammation. Genes, temperament or early experience—including childhood trauma, neglect or abuse—may each play a role in predisposing someone to both disorders."