Here’s an interesting study showing that women with untreated obstructive sleep apnea have worse levels of brain damage compared with men. In this particular study, the cingulum bundle and the anterior cingulate cortex, areas which are involved in decision-making and mood regulation, were most affected. The lead investigator was also the first to show that sleep apnea causes major damage to brain cells. As with every paper that studies sleep apnea and brain damage, the authors are always quick to add that they’re not sure if sleep apnea causes brain damage or brain damage causes sleep-breathing disorders. Based on all that we know about the effects of untreated obstructive sleep apnea, I would go with the former explanation.