I’ve written numerous times in the past about how various areas of the brain can be injured from untreated obstructive sleep apnea. Studies have shown that sleep apnea patients have lowered brain density levels in areas that control memory, executive function, and autonomic control. Despite all the bad news about the effects of untreated obstructive sleep apnea on the brain, here’s some good news: A recent study showed that the brain can regenerate even after 3 months of CPAP usage. Brain volume actually increased significantly, and neuropsychological tests improved significantly as well. The only caveat was that this study was supported by the Respironics Foundation (not that there’s anything wrong with that).