The likelihood that short term pain will become long term pain may depend on the wiring of your brain. Or, the wiring of your brain may depend on the extent of your chronic pain. That less-than-definitive news comes from researchers at Northwestern University’s Feinberg School of Medicine, where doctors conducted regular brain scans over the course of one year on 46 subjects who had experienced a first episode of back pain that had already lasted four to 16 weeks. The Los Angeles Times reports that the researchers found that within two months of recruiting patients, discernible differences in the structure of “white matter” could distinguish subjects whose pain persisted from those whose pain was beginning to resolve. The Times reports that by the 12-month mark, the structural differences in white matter allowed researchers to distinguish — without error — subjects whose pain had disappeared from those whose pain was persistent. Compared to subjects whose pain resolved, subjects whose pain would become chronic also showed differences in the density of connections that lashed their nucleus accumbens — a central structure in the brain rewards, motivation, pleasure and reinforcement learning circuit — together with their medial prefrontal cortex, a switchboard for decision-making, emotional response and long-term memory. Wait, there’s more. As time passed, the white matter and brain connections of subjects with back pain that went away looked much more like those of healthy control subjects than they did like the brains of subjects whose pain became chronic. The researchers have yet to answer the big question: did the chronic pain cause the brain structure to change or did the brain structure cause the pain to become chronic? Yes, reader, it hurts, but more research is needed.