Is there an explanation of what happens in the brain as we age that causes sleep to worsen?
I think that there are probably some structural changes that are going on in the brain as we age, and some underlying chemical changes as well. Just as the body changes with age, so too does the brain. Unfortunately, we tend to lose certain aspects of brain function with age. The parts of brain function that we lose are areas of the cortex, and the cortex is responsible for generating sleep at nighttime. When we lose some of that cortical function, we're just not able to generate the same degree of sleep as we were when we were younger. And these changes start earlier than you may think, when we're in our early 30s and 40s.
How prevalent are sleep problems among aging populations?
One of the biggest problems we see in sleep disorders medicine is sleep issues in older people. In part it's the result of the changes in brain function, but it's also a result of the stresses and difficulties inherent in later life.
What is the most common complaint?
Generally, older people complain of waking up in the middle of the night and having only fragmented sleep after that. They tend not to have too much difficulty falling asleep, but after a few hours of sleep, their brains say, "I'm done," then they start waking up and having fragmented sleep throughout the nighttime. They tend to wake up very early in the morning, four or five o'clock or so, not being able to return to sleep.