The hypothalamus, a peanut-sized structure deep inside the brain, contains groups of nerve cells that act as control centers affecting sleep and arousal. Within the hypothalamus is the suprachiasmatic nucleus (SCN) – clusters of thousands of cells that receive information about light exposure directly from the eyes and control your behavioral rhythm. Some people with damage to the SCN sleep erratically throughout the day because they are not able to match their circadian rhythms with the light-dark cycle. Most blind people maintain some ability to sense light and are able to modify their sleep/wake cycle.
The National Sleep Foundation reports that insomnia is common among those who are depressed and notes that people with insomnia have a much higher risk of becoming depressed. (11) Research from the Department of Psychology at the University of North Texas shows that depression may affect many aspects of sleep, from getting to sleep to staying asleep. By treating depression using St. John’s wort, you may be able to find that restful sleep your body and mind longs for. (12)
At some point or another, most of us will experience a short, unpleasant bout of insomnia. Often, it’s the result of stress or a change in routine (like a new work schedule or having a baby), or medications that mess with sleep like antidepressants, blood pressure meds, allergy meds, and corticosteroids. The good news is that usually, once you find a way to deal with the situation, your sleep pattern will get back to normal.
An ultra short episode of sleep is sufficient to promote declarative memory performance. Lahl O, Wispel C, Willigens B. Journal of sleep research, 2008, Apr.;17(1):1365-2869. But try to avoid napping after 3:00 or 4:00pm, as this can make it harder to fall asleep at bedtime. Effects of afternoon "siesta" naps on sleep, alertness, performance, and circadian rhythms in the elderly. Monk TH, Buysse DJ, Carrier J. Sleep, 2002, Feb.;24(6):0161-8105.
However, if you’re increasing your sleep debt over a longer period of time- say, if you’ve just had a child and aren’t able to get a full eight hours every night- you can’t easily make it up over just a few nights. In cases like these, it may take a few weeks to really fill your sleep debt. Your best bet is to plan a vacation or stay-cation with a light schedule and no obligations, and then turn off your alarm clock and go to bed and wake up when it feels natural. This will “reset” your sleep system so that while you may be sleeping 12 hours a night at the beginning, you’ll eventually settle back in to the amount that is your basal sleep need.
Adjust the thermostat. If you’re too hot or too cold at bedtime, sleep isn’t going to come easy. While there’s no ideal temperature for everyone, most people sleep comfortably when the bedroom is between 60 and 67 degrees. As you start to feel drowsy, your body temperature drops, which in turn helps you drift off to sleep. A cooler bedroom facilitates that. Don’t cool it off too much, though — shivering in bed isn’t conducive to a good night’s sleep.