Neuroscience has done much to help us understand what occurs in the brain of the addict, and now it also offers us a better understanding of what occurs for family members, specifically as it relates to enabling behavior. The brain is wired to react empathetically to someone in pain in order to warn others of danger and elicit help. Functional MRI scans show that when watching someone undergo electric shock, the observer's brain lights up in the same areas in which the brain of the person in pain lights up.(Bufalari, Ilaria et al. (2007) Empathy for Pain and Touch in the Human Somatosensory cortex. Cerebral Cortex. 17:2553-2561)
One doesn't have to witness the painful experience for the brain to react, simply seeing a person act as if he or she is in pain causes the brain to light up. When the person in pain is a family member, the reaction to his or her pain is exponentially stronger.