By Dr. Mercola
The brain chemical hypocretin, a neurotransmitter that helps keep you awake, is most widely known for its role in the sleeping disorder known as narcolepsy.
Narcoleptics, who uncontrollably fall asleep during the day and have much higher rates of depression than the general population, are unable to produce hypocretin. This not only interferes with their sleep-wake cycle, but also may also disrupt their emotional state – a new finding that has implications for everyone.
Hypocretin May Regulate Your Levels of Happiness
A new study, which used epilepsy patients who had special electrodes implanted in their brains that could monitor hypocretin levels, found that levels of the neurotransmitter soared during positive emotions, anger, social interactions and upon awakening.1
Hypocretin has been previously associated with reward-seeking behaviors, and the researchers suggested it may have a very specific role in human arousal and happiness as well. The study’s lead author, Dr. Jerome Siegel, told the New York Times:2
“This [study] shows that hypocretin is related to a particular kind of arousal … There is an arousal system in the brain whose function is keeping you awake for pleasure, to get rewards. It is related to positive effects, and in its absence you have a deficit in pleasure seeking.”
This explains why people with narcolepsy, who are lacking hypocretin, also commonly suffer from depression. Interestingly, it also suggests there may be other arousal systems in your brain, driven by different brain chemicals, that may be in charge of regulating other specific emotions.
A Warning About Hypocretin-Blocking Sleeping Pills
If an important new biological pathway is discovered you can bet your bottom dollar that the drug companies will not be far behind to manipulate that pathway in some way that will not correct the problem, but merely relieve the symptoms and make them a boatload of money. And that is precisely what has happened.
The U.S. Food and Drug Administration (FDA) has accepted a new drug application for Suvorexant, a new insomnia medication made by Merck.3 This is the same company that brought you Vioxx, which killed 60,000 before being pulled from the market.
The new drug works by targeting hypocretin, temporarily blocking it to help you fall asleep, or, as the New York Times put it, “essentially causing narcolepsy for a night.”4
The concern is that if reduced hypocretin may be responsible for causing depression in narcoleptics, could it also cause depression, or interfere with mood, in healthy people using the hypocretin-blocking drug Suvorexant? So far Merck claims no connection has been found, but there is likely reason for caution:5
“The initial reports are rosy,” Dr. Siegel told the New York Times, “But they come from a drug company with an enormous investment. And there is a long list of drugs acting on the brain whose severe problems were only identified after millions of people were taking them.”
More Proof Lack of Sleep Leads to Weight Gain
Research has only scratched the surface of the far-reaching implications of a disrupted sleep-wake cycle. But in addition to impacting your emotions, it’s known that a lack of sleep causes changes in the hunger and satiety hormones ghrelin and leptin – changes that impact your food intake and ultimately your weight.
The latest research showed the effects of sleeping just five hours a night for five days. The study participants actually burned more energy than those who slept longer, but they had less restraint when it came to mealtime. The sleep-deprived subjects ended up eating more, so that despite their increased energy burning they gained nearly two pounds, on average, during the five-day study.6
“Our findings suggest that increased food intake during insufficient sleep is a physiological adaptation to provide energy needed to sustain additional wakefulness; yet when food is easily accessible, intake surpasses that needed … These findings provide evidence that sleep plays a key role in energy metabolism. Importantly, they demonstrate physiological and behavioral mechanisms by which insufficient sleep may contribute to overweight and obesity.”
The good news is that the opposite also held true: when participants started getting more sleep, they subsequently started to eat less and lose weight.
Too Little Sleep Wreaks Havoc on Your Insulin Levels, Leads to Food Cravings
Sleep deprivation tends to lead to food cravings, particularly for sweet and starchy foods. Researchers have suggested that these sugar cravings stem from the fact that your brain is fueled by glucose (blood sugar); therefore, when lack of sleep occurs, and your brain is unable to properly respond to insulin (which drives glucose into brain cells) your brain becomes desperate for carbohydrates to keep going. If you're chronically sleep deprived, consistently giving in to these sugar cravings will virtually guarantee that you'll gain weight.
Getting too little sleep also dramatically decreases the sensitivity of your insulin receptors, which will raise your insulin levels. This too is a surefire way to gain weight, as the elevated insulin will seriously impair your body's ability to burn and digest fat.
According to research published in the Annals of Internal Medicine,7 after four nights of sleep deprivation (sleep time was only 4.5 hours per night), study participants' insulin sensitivity was 16 percent lower, while their fat cells' insulin sensitivity was 30 percent lower, and rivaled levels seen in those with diabetes or obesity.
Sleep Deprivation Linked to Psychiatric Disorders
Getting back to the link between sleep, or lack of it, and mood, sleep deprivation is linked to psychiatric disorders such as anxiety and bipolar depression, while getting the right amount of sleep has been linked to positive personality characteristics such as optimism and greater self-esteem, as well as a greater ability to solve difficult problems.8
So there’s no doubt about it: too little sleep can seriously impact your mood and your ability to be happy. If you feel well-rested in the morning, that's a good sign that your sleep habits are just fine. But if not, you might want to investigate your sleep patterns more closely.
10 Reasons Why You Might Have Trouble Sleeping
There are many factors that can influence your sleep. For my complete recommendations and guidelines that can help you improve your sleep, please see my article 33 Secrets to a Good Night's Sleep. Following are 10 often-overlooked factors to address if you’re having trouble with your sleep:
- Too Much Light in Your Room
Even the tiniest bit of light in the room, including those emitted by electronic devices, can disrupt your pineal gland's production of melatonin and serotonin, thereby disrupting your sleep cycle.
So close your bedroom door, install black-out drapes, use a sleep mask, get rid of night-lights, and refrain from turning on any light during the night, even when getting up to go to the bathroom. If you have to use a light you can use a red flashlight, as that wavelength of light has a minimal impact on melatonin production.
- Exercising Too Close to Bedtime
Exercising for at least 30 minutes per day can improve your sleep. However, don't exercise too close to bedtime (generally not within the three hours before) or it may keep you awake.
- Drinking Alcohol Before Bed
Although alcohol will make you drowsy, the effect is short lived and you will often wake up several hours later, unable to fall back asleep. Alcohol can also keep you from entering the deeper stages of sleep, where your body does most of its healing.
- Your Bedroom is Too Warm
Many people keep their homes and particularly their upstairs bedrooms too warm. Studies show that the optimal room temperature for sleep is quite cool, between 60 to 68 degrees F. Keeping your room cooler or hotter can lead to restless sleep. When you sleep, your body's internal temperature drops to its lowest level, generally about four hours after you fall asleep.
Scientists believe a cooler bedroom may therefore be most conducive to sleep, since it mimics your body's natural temperature drop.
- Caffeine is Keeping You Awake
Caffeine has a half-life of five hours, which means some will still be in your system even 10 hours later, and 12.5% 20 hours later (see the problem?). Plus, in some people caffeine is not metabolized efficiently, leaving you feeling its effects even longer after consumption. So, an afternoon cup of coffee or tea will keep some people from falling asleep at night. Be aware that some over the counter medications contain caffeine as well (for example, diet pills).
- You're Watching the Clock
The more you watch the clock when you wake up in the middle of the night, the more stressed and anxious you will become, and the more you may actually "train" yourself to start awakening at the same time each night. The solution is simple: Remove the clock from your view so you actually have to sit up or change positions to see the clock.
- Watching TV to Help You Fall Asleep
The artificial glow from your TV can serve as a stimulus for keeping you awake and, possibly, eating, when you should really be asleep. Further, computer and TV screens (and most light bulbs) emit blue light, to which your eyes are particularly sensitive simply because it's the type of light most common outdoors during daytime hours. As a result, it can disrupt your melatonin production and further interfere with your sleep.
- Worrying in the Middle of the Night
If stress keeps you up at night, try keeping a "worry journal" next to your bedside so you can jot down your thoughts there and clear them from your head. The Emotional Freedom Technique (EFT) can also help balance your body's bioenergy system and resolve some of the emotional stresses that are contributing to your insomnia at a very deep level. The results are typically long lasting and improvement is remarkably rapid.
- Eating Too Close to Bedtime
Although you might struggle with this initially, it is ideal to avoid eating any foods three hours before bed, as this will optimize your blood sugar, insulin and leptin levels and contribute to overall good health.
The nicotine in cigarettes is a stimulant, which can keep you awake much as though you just drank a cup of coffee.