The mental effects of sleep deprivation

The mental effects of sleep deprivation

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The mental effects of sleep deprivation

The average adult needs about 8 and 1/2 hours of sleep per night, says Dr. Brian Murray, MD, a sleep scientist at Sunnybrook Health Sciences Centre in Toronto. Sadly, it's not true that the older you get, the less sleep you need, he adds. Whether you're 20 or 90 years old, your body needs the same amount of sleep to function.

So what happens to your body when you don't get enough sleep? Read on!

0 hours:

Not sleeping for an entire night can be very dangerous, especially if you have to drive in the morning. "The next day, you're as impaired as a person who has drunk more than the legal limit," says Dr. Murray. When you don't sleep, you lose the ability to sustain attention—you may have trouble focusing your eyes and may even nod off. And it only takes three seconds of dozing behind the wheel to drift into another lane and cause an accident.

4 hours or less:
Sleeping for four hours means you've achieved core sleep, which is the minimum your body needs to restore and recover cells, says Dr. Murray. But you may have trouble with good judgment, memory and mood stability. Many people come to Dr. Murray complaining of poor memories; once he helps them improve their sleep patterns, their memories improve. "It isn't that their memories got better," he says. "It's just that they were more awake to form memories."

5 to 7 hours:
If you sleep five to seven hours per night, you're achieving what sleep researchers call luxury sleep. This is what your brain needs to function properly, says Dr. Murray, but it still isn't enough for you to be at your best. "Some people get by on six hours," Dr. Murray says. "It's kind of like the lights are on, but nobody's home."

7 and 1/2 to 8 and 1/2 hours:
Murray says that 8 and 1/2 hours is the amount of shut-eye most people need to function optimally. Of course, many people who get the desired 8 and 1/2 hours still complain of feeling tired throughout the day, especially after lunch. This is what Murray calls the "post-lunch dip," and it's completely normal. Most people feel tired from 2 to 4 p.m. because of the body's natural circadian rhythm. If you feel dozy in the afternoon, try going outside or standing in front of a light-filled window. If you take an afternoon nap, however long you sleep counts toward your daily total. So a two-hour nap means you only need six hours of sleep that night.

More than 9 hours:
If you are sleeping more than nine hours per night, you may be oversleeping, says Dr. Murray.  He advises lying in bed only when you intend to fall asleep, so that your bedroom becomes an area dedicated solely to sleeping.

Are you sleep deprived?
If you have to set an alarm clock to wake yourself up each morning, you're likely not getting enough sleep. "If you slept to your needs, you would wake up spontaneously," says Dr. Murray. "Waking up to an alarm clock is a societal determinant, not a biological one."

3 tips to help you sleep better:

1. Figure out your sleep efficacy
Your sleep efficacy is the number of hours slept divided by the number of hours spent in bed, then multiplied by 100. Dr. Murray says a good goal to work toward is a sleep efficacy of 85. Your sleep efficacy reveals if you're giving your body enough time to wind down at night or if you're spending too much time in bed doing other things, like watching TV or reading on your iPad.

2. Set good sleep behaviours
Your first sleep goal should be to go to bed and wake up at the same times each day, so that your body sets a regular rhythm. Your second goal should be to sleep in a cool, dark, quiet place, says Dr. Murray.

3. Get help if you need it
Many people struggle to fall asleep at night and sometimes turn to medication. Over-the-counter products can be used for occasional sleeplessness. If you consistently have difficulty falling asleep, you should see your family doctor or visit a sleep clinic.

For more sleeping tips, check out how you can lose weight while sleeping.
This story was originally titled "Your Body On Sleep" in the May 2014 issue.
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The mental effects of sleep deprivation