As a migraine sufferer I feel like I can confirm this, anecdotally. Often when I fight a migraine off midday it takes at least a 10 min nap to get back to somewhat normal feeling. I don't know how to describe what that nap can feel like. It feels a lot different than any other sort of sleep. Like the mental equivalent of standing on the top of a train that's descending down into a deep cavern and then back up to the light.