TIME Books

Go the F-ck to Sleep Has a Sequel

You Have to F--king Eat Adam Mansbach
Akashic Books

It's called 'You Have to F-cking Eat'

The author of the bestselling humorous children’s book Go the F-ck to Sleep is back, and this time he’s tackling the treacherous minefield of kids’ insane eating habits.

Adam Mansbach’s new book, You Have to F-cking Eat is a “long-awaited sequel about the other great parental frustration: getting your little angel to eat something that even vaguely resembles a normal meal,” according to the publisher, Akashic books.

Go the F-ck to Sleep was marketed at frustrated parents trying to get their kids to sleep, and despite the profanities—or perhaps because of them—it debuted at #1 on the New York Times Bestseller list and sold over 1.5 million copies worldwide.

You Have to F-cking Eat, which is illustrated by Owen Brozman, will be available to purchase Nov. 12.

TIME Paycheck Friday

5 Unique Sleep Gadgets for Under $60

Come on, you're making some decent money now. Live a little! Consider blowing your paycheck on these worthy splurges.

Cool or Hot Pillow Pad ($32.75)

GelO_Cool_Pillow_Mat
Human Creations

Your blind date was going well until you embarrassed yourself by passing gas more loudly than a tanker truck replenishing the pumps at 7-11. Back home – alone, natch – your face gets red hot every time you replay the unfortunate incident in your head.

The Gel’O Cool Pillow Mat can cool your face down as you’re trying to fall asleep. Just pop it in the fridge or freezer before bedtime, place it on top of your pillow and then lay your shameful head down. During the winter months, you can shove it in the microwave to heat it up instead.

[Human Creations]

White Noise Machine ($54.95)

LectroFan
LectroSound

You live in a studio apartment with paper-thin walls above a rowdy bar and below a 24-hour daycare center full of teething babies with colic. Next door is a 24-hour doggy day care heralded for its innovative use of outdoor-only barking zones. Across the street is a gun range. That’s 24 hours, too.

This highly-rated white noise/fan-sounds machine is small enough to travel with,

but gets loud enough to drown out even the most egregious hoopla. Not that you’d want to take a vacation: Your place sounds nice!

[Amazon]

Blue-Glow Sleep Mask ($39.99)

sleep mask
Sharper Image

You bring your work home with you. It’s not easy collecting soil samples for a living. All the second-guessing! Did I use the correct trowel? Should I be rotating my wrist to the left or to the right? And how many degrees?!

Thoughts like this normally keep you up at night, but this fancy sleep mask can help you relax your mind by bathing your eyeballs in a soft blue light meant to shift your brain from its beta phase to its alpha phase. Even without the blue-glow feature, the wraparound mask blocks out light while leaving room for your eyes to breathe.

[Sharper Image]

NASA Light Bulb ($59.95)

NASA bulb
Hammacher Schlemmer

At first blush, a $60 light bulb sounds expensive. But you know what’s marginally more expensive? Going to space. That’s what you’d otherwise have to do in order to use this thing. So if you think about it, this NASA light bulb pretty much pays for itself after all the trips you won’t take to space.

You’re supposed to use it in a bedside lamp for a half hour before you go to sleep so it can ramp up your melatonin levels. You can optionally use it at your next dinner party to see if you can get your guests to pass out in their soup.

[Hammacher Schlemmer]

Sonic Boom Alarm Clock ($39.10)

sonic boom
Sonic Bomb

“Enough with trying to get me to fall asleep!” you bellow, slamming your hammy fists on your particle-board workspace as anger-spit forms in the corners of your mouth. “I can’t wake up!”

For you, there’s this ridiculously loud alarm clock.

I sleep and wake like a normal person, so this thing sounds awful. A 113-decibel alarm? Pass. A vibration doodad so powerful it can shake your entire bed? No, thank you. Flashing red lights? I’m good, thanks. There’s nothing quite like being terrified first thing in the morning.

[Amazon]

TIME Mental Health/Psychology

Your Dreams Get More Bizarre as the Night Goes On

As the night wears on, your dreams escalate in weirdness, finds a small new study published in the journal Dreaming.

For two nights, the researchers outfitted 16 people with a sleep-monitoring eyelid sensor and head sensor, then proceeded to wake each person up at four different times in the night. Sleepers were asked to say what they’d been dreaming, and in the morning, they listened to their dreams and answered questions about them, like how related the dreams were to their waking life.

“We found that dreams were increasing in bizarreness from the early to late night,” says study author Dr. Josie Malinowski, a lecturer in cognitive psychology at the University of Bedfordshire in the U.K. The later dreams were more fantastical, impossible, and completely unlikely to ever happen in real life, “like a wild animal tearing up your back garden,” she says. Dreams also tend to become more emotional—in equal ways positive and negative—as the night progresses.

In the early stages of sleep, people dream more about media they’d consumed during the day, like a movie they’d watched or book they’d read. Dreams about events that happened during waking life, however, were more robust later in the night.

Some dream researchers, including Dr. Malinowski, believe you can prime the brain to dream about a particular topic through “dream incubation,” and that dreams might be able to help us problem-solve. Exploring these dreams can help people understand their own behavior, thoughts and feelings, Dr. Malinowski says.

And through her research, she’s trying to get people to take dream therapy more seriously. “People really enjoy it,” she told TIME. “Dreams are like a safe space. People feel like they haven’t generated them because they’re often so bizarre. [But] they’re a safe way to explore the self.”

TIME Mental Health/Psychology

Less Than 5 Hours of Sleep Leads to False Memories

Skimping on sleep wears down your body in so many ways: it worsens cognitive function, slows reaction time, and makes learning more difficult. (The list goes on and on: after reading our new feature about the power of sleep, you might just scare yourself sleepy.)

That’s quite enough consequences without piling on the results of a recent study in Psychological Science, which found that sleep deprivation is linked to false memories. Among the 193 people tested, those who got 5 or fewer hours of sleep for just one night were significantly more likely to say they’d seen a news video when they actually hadn’t.

There’s more than just fantastical daydreaming at stake. False memories in the form of eyewitness misidentifications are thought to be the number-one cause of wrongful convictions in the U.S., the study authors write, so sleep deprivation could have consequences beyond the scope of your own health.

The study also discovered that students were more prone to researchers’ false suggestions when they hadn’t slept more than five hours. They wove those suggestions into their responses 38% of the time, while the group that got plenty of sleep did so 28% of the time. That’s probably because sleep deprivation leads to problems encoding new information, the authors write.

“Our results also suggest that total sleep deprivation may not be necessary to increase false memory,” they write in the study. Losing just a few hours could be enough to lead you to dream up facts during waking life.

TIME sleep

The Power of Sleep

sleep illustration
Photo-Illustration by Timothy Goodman for TIME

New research shows a good night's rest isn't a luxury--it's critical for your brain and for your health

When our heads hit the pillow every night, we tend to think we’re surrendering. Not just to exhaustion, though there is that. We’re also surrendering our mind, taking leave of our focus on sensory cues, like noise and smell and blinking lights. It’s as if we’re powering ourselves down like we do the electronics at our bedside–going idle for a while, only to spring back into action when the alarm blasts hours later.

That’s what we think is happening. But as scientists are now revealing, that couldn’t be further from the truth.

In fact, when the lights go out, our brains start working–but in an altogether different way than when we’re awake. At night, a legion of neurons springs into action, and like any well-trained platoon, the cells work in perfect synchrony, pulsing with electrical signals that wash over the brain with a soothing, hypnotic flow. Meanwhile, data processors sort through the reams of information that flooded the brain all day at a pace too overwhelming to handle in real time. The brain also runs checks on itself to ensure that the exquisite balance of hormones, enzymes and proteins isn’t too far off-kilter. And all the while, cleaners follow in close pursuit to sweep out the toxic detritus that the brain doesn’t need and which can cause all kinds of problems if it builds up.

This, scientists are just now learning, is the brain on sleep. It’s nature’s panacea, more powerful than any drug in its ability to restore and rejuvenate the human brain and body. Getting the recommended seven to eight hours each night can improve concentration, sharpen planning and memory skills and maintain the fat-burning systems that regulate our weight. If every one of us slept as much as we’re supposed to, we’d all be lighter, less prone to developing Type 2 diabetes and most likely better equipped to battle depression and anxiety. We might even lower our risk of Alzheimer’s disease, osteoporosis and cancer.

The trouble is, sleep works only if we get enough of it. While plenty of pills can knock us out, none so far can replicate all of sleep’s benefits, despite decades’ worth of attempts in high-tech pharmaceutical labs.

Which is why, after long treating rest as a good-if-you-can-get-it obligation, scientists are making the case that it matters much more than we think. They’re not alone in sounding the alarm. With up to 70 million of us not getting a good night’s sleep on a regular basis, the Centers for Disease Control and Prevention considers insufficient sleep a public-health epidemic. In fact, experts argue, sleep is emerging as so potent a factor in better health that we need a societal shift–and policies to support it–to make sleep a nonnegotiable priority.

THE CONSEQUENCES OF SKIMPING

Despite how great we feel after a night’s rest–and putting aside what we now know about sleep’s importance–we stubbornly refuse to swallow our medicine, pushing off bedtime and thinking that feeling a little drowsy during the day is an annoying but harmless consequence. It’s not. Nearly 40% of adults have nodded off unintentionally during the day in the past month, and 5% have done so while driving. Insomnia or interrupted sleep nearly doubles the chances that workers will call in sick. And half of Americans say their uneven sleep makes it harder to concentrate on tasks.

Those poor sleep habits are trickling down to the next generation: 45% of teens don’t sleep the recommended nine hours on school nights, leading 25% of them to report falling asleep in class at least once a week, according to a National Sleep Foundation survey. It’s a serious enough problem that the American Academy of Pediatrics recently endorsed the idea of starting middle and high schools later to allow for more adolescent shut-eye.

Health experts have been concerned about our sleep-deprived ways for some time, but the new insights about the role sleep plays in our overall health have brought an urgency to the message. Sleep, the experts are recognizing, is the only time the brain has to catch its breath. If it doesn’t, it may drown in its own biological debris–everything from toxic free radicals produced by hard-working fuel cells to spent molecules that have outlived their usefulness.

“We all want to push the system, to get the most out of our lives, and sleep gets in the way,” says Dr. Sigrid Veasey, a leading sleep researcher and a professor of medicine at Perelman School of Medicine at the University of Pennsylvania. “But we need to know how far we can really push that system and get away with it.”

Veasey is learning that brain cells that don’t get their needed break every night are like overworked employees on consecutive double shifts–eventually, they collapse. Working with mice, she found that neurons that fire constantly to keep the brain alert spew out toxic free radicals as a by-product of making energy. During sleep, they produce antioxidants that mop up these potential poisons. But even after short periods of sleep loss, “the cells are working hard but cannot make enough antioxidants, so they progressively build up free radicals and some of the neurons die off.” Once those brain cells are gone, they’re gone for good.

After several weeks of restricted sleep, says Veasey, the mice she studied–whose brains are considered a good proxy for human brains in lab research–“are more likely to be sleepy when they are supposed to be active and have more difficulty consolidating [the benefits of] sleep during their sleep period.”

It’s the same thing that happens in aging brains, she says, as nerve cells get less efficient at clearing away their garbage. “The real question is: What are we doing to our brains if we don’t get enough sleep? If we chronically sleep-deprive ourselves, are we really aging our brains?” she asks. Ultimately, the research suggests, it’s possible that a sleep-deprived brain belonging to a teen or a 20-year-old will start to look like that of a much older person.

“Chronic sleep restriction is a stress on the body,” says Dr. Peter Liu, professor of medicine at Harbor-UCLA Medical Center and L.A. Biomedical Research Institute. And the cause of that sleep deprivation doesn’t always originate in family strife, financial concerns or job-related problems. The way we live now–checking our phones every minute, hyperscheduling our days or our kids’ days, not taking time to relax without a screen in front of our faces–contributes to a regular flow of stress hormones like cortisol, and all that artificial light and screen time is disrupting our internal clocks. Simply put, our bodies don’t know when to go to sleep naturally anymore.

This is why researchers hope their new discoveries will change once and for all the way we think about–and prioritize–those 40 winks.

GARBAGEMEN FOR YOUR BRAIN

“I was nervous when I went to my first sleep conference,” says Dr. Maiken Nedergaard, the chatty and inquisitive co-director of the Center for Translational Neuromedicine at the University of Rochester. “I was not trained in sleep, and I came to it from the outside.” In fact, as a busy mother and career woman, she saw sleep the way most of us probably do: as a bother. “Every single night, I wanted to accomplish more and enjoy time with my family, and I was annoyed to have to go to bed.”

Because she’s a neuroscientist, however, Nedergaard was inclined to ask a seemingly basic question: Why do our brains need sleep at all? There are two competing evolutionary theories. One is that sleeping organisms are immobile and therefore less likely to be easy targets, so perhaps sleep provided some protection from prey. The time slumbering, however, took away from time spent finding food and reproducing. Another points out that sleeping organisms are oblivious to creeping predators, making them ripe for attack. Since both theories seem to put us at a disadvantage, Nedergaard thought there had to be some other reason the brain needs those hours offline.

All organs in the body use energy, and in the process, they spew out waste. Most take care of their garbage with an efficient local system, recruiting immune cells like macrophages to gobble up the garbage and break it down or linking up to the network of vessels that make up the lymph system, the body’s drainage pipes.

The brain is a tremendous consumer of energy, but it’s not blanketed in lymph vessels. So how does it get rid of its trash? “If the brain is not functioning optimally, you’re dead evolutionarily, so there must be an advantage to exporting the garbage to a less critical organ like the liver to take care of it,” says Nedergaard.

Indeed, that’s what her research shows. She found that an army of previously ignored cells in the brain, called glial cells, turn into a massive pump when the body sleeps. During the day, glial cells are the unsung personal assistants of the brain. They cannot conduct electrical impulses like other neurons, but they support them as they send signals zipping along nerve networks to register a smell here and an emotion there. For decades, they were dismissed by neuroscientists because they weren’t the actual drivers of neural connections.

But Nedergaard found in clinical trials on mice that glial cells change as soon as organisms fall asleep. The difference between the waking and sleeping brain is dramatic. When the brain is awake, it resembles a busy airport, swelling with the cumulative activity of individual messages traveling from one neuron to another. The activity inflates the size of brain cells until they take up 86% of the brain’s volume.

When daylight wanes and we eventually fall asleep, however, those glial cells kick into action, slowing the brain’s electrical activity to about a third of its peak frequency. During those first stages of sleep, called non-REM (rapid eye movement), the firing becomes more synchronized rather than haphazard. The repetitive cycle lulls the nerves into a state of quiet, so in the next stage, known as REM, the firing becomes almost nonexistent. The brain continues to toggle back and forth between non-REM and REM sleep throughout the night, once every hour and a half.

At the same time, the sleeping brain’s cells shrink, making more room for the brain and spinal cord’s fluid to slosh back and forth between them. “It’s like a dishwasher that keeps flushing through to wash the dirt away,” says Nedergaard. This cleansing also occurs in the brain when we are awake, but it’s reduced by about 15%, since the glial cells have less fluid space to work with when the neurons expand.

This means that when we don’t get enough sleep, the glial cells aren’t as efficient at clearing the brain’s garbage. That may push certain degenerative brain disorders that are typical of later life to appear much earlier.

Both Nedergaard’s and Veasey’s work also hint at why older brains are more prone to developing Alzheimer’s, which is caused by a buildup of amyloid protein that isn’t cleared quickly enough.

“There is much less flow to clear away things in the aging brain,” says Nedergaard. “The garbage system picks up every three weeks instead of every week.” And like any growing pile of trash, the molecular garbage starts to affect nearby healthy cells, interfering with their ability to form and recall memories or plan even the simplest tasks.

The consequences of deprived sleep, says Dr. Mary Carskadon, professor of psychiatry and human behavior at Brown University, are “scary, really scary.”

RIGHTSIZING YOUR SLEEP

All this isn’t actually so alarming, since there’s a simple fix that can stop this nerve die-off and slow the brain’s accelerated ride toward aging. What’s needed, says Carskadon, is a rebranding of sleep that strips away any hint of its being on the sidelines of our health.

As it is, sleep is so undervalued that getting by on fewer hours has become a badge of honor. Plus, we live in a culture that caters to the late-nighter, from 24-hour grocery stores to online shopping sites that never close. It’s no surprise, then, that more than half of American adults don’t get the recommended seven to nine hours of shut-eye every night.

Whether or not we can catch up on sleep–on the weekend, say–is a hotly debated topic among sleep researchers; the latest evidence suggests that while it isn’t ideal, it might help. When Liu, the UCLA sleep researcher and professor of medicine, brought chronically sleep-restricted people into the lab for a weekend of sleep during which they logged about 10 hours per night, they showed improvements in the ability of insulin to process blood sugar. That suggests that catch-up sleep may undo some but not all of the damage that sleep deprivation causes, which is encouraging given how many adults don’t get the hours they need each night. Still, Liu isn’t ready to endorse the habit of sleeping less and making up for it later. “It’s like telling people you only need to eat healthy during the weekends, but during the week you can eat whatever you like,” he says. “It’s not the right health message.”

Sleeping pills, while helpful for some, are not necessarily a silver bullet either. “A sleeping pill will target one area of the brain, but there’s never going to be a perfect sleeping pill, because you couldn’t really replicate the different chemicals moving in and out of different parts of the brain to go through the different stages of sleep,” says Dr. Nancy Collop, director of the Emory University Sleep Center. Still, for the 4% of Americans who rely on prescription sleep aids, the slumber they get with the help of a pill is better than not sleeping at all or getting interrupted sleep. At this point, it’s not clear whether the brain completes the same crucial housekeeping duties during medicated sleep as it does during natural sleep, and the long-term effects on the brain of relying on sleeping pills aren’t known either.

Making things trickier is the fact that we are unaware of the toll sleep deprivation takes on us. Studies consistently show that people who sleep less than eight hours a night don’t perform as well on concentration and memory tests but report feeling no deficits in their thinking skills. That just perpetuates the tendency to dismiss sleep and its critical role in everything from our mental faculties to our metabolic health.

The ideal is to reset the body’s natural sleep-wake cycle, a matter of training our bodies to sleep similar amounts every night and wake up at roughly the same time each day. An even better way to rediscover our natural cycle is to get as much exposure to natural light as possible during the day, while limiting how much indoor lighting, including from computer and television screens, we see at night. And of course, the best way to accomplish that is by making those seven to nine hours of sleep a must–not a luxury.

“I am now looking at and thinking of sleep as an ‘environmental exposure,'” says Brown University’s Carskadon–which means we should look at sleep similarly to how we view air-pollution exposure, secondhand smoke or toxins in our drinking water. If she and other researchers have their way, checking up on sleep would be a routine part of any physical exam, and doctors would ask about our sleep habits in the same way they query us about diet, stress, exercise, our sex life, our eyesight–you name it. And if we aren’t sleeping enough, they might prescribe a change, just as they would for any other bad health habit.

Some physicians are already taking the initiative, but no prescription works unless we actually take it. If our work schedule cuts into our sleep time, we need to make the sleep we get count by avoiding naps and exercising when we can during the day; feeling tired will get us to fall asleep sooner. If we need help dozing off, gentle exercises or yoga-type stretching can also help. Creating a sleep ritual can make sleep something we look forward to rather than something we feel obligated to do, so we’re more likely to get our allotted time instead of skipping it. A favorite book, a warm bath or other ways to get drowsy might prompt us to actually look forward to unwinding at the end of the day.

Given what scientists are learning about how much the body–and especially the brain–needs a solid and consistent amount of sleep, in-the-know doctors aren’t waiting for more studies to prove what we as a species know intuitively: that cheating ourselves of sleep is depriving us from taking advantage of one of nature’s most powerful drugs.

“We now know that there is a lasting price to pay for sleep loss,” says Veasey. “We used to think that if you don’t sleep enough, you can sleep more and you’ll be fine tomorrow. We now know if you push the system enough, that’s simply not true.”

–WITH REPORTING BY MANDY OAKLANDER AND ALEXANDRA SIFFERLIN/NEW YORK CITY

TIME neuroscience

Alzheimer’s Linked to Sleeping Pills and Anti-Anxiety Drugs

New research suggests that people who take benzodiazepines may have a higher risk of developing Alzheimer’s

About 9 million Americans rely on sleeping pills or some sort of sedative to doze off at night, and 11% of middle-aged women take anti-anxiety medications. The most common of these include benzodiazapines, and now scientists say the drugs are associated with a higher risk of Alzheimer’s.

In a report published Wednesday in The BMJ, researchers say that among 1,796 people with Alzheimer’s disease and 7,184 controls, those who have used benzodiazepines showed a 51% higher risk of the neurodegenerative disorder. Among people who took the drugs more than 180 days, the risk escalated to about two-fold higher.

Previous studies have linked the drugs to memory and cognitive problems, but primarily in those taking them short term. But in the current study, in which the scientists, led by Sophie Billioti de Gage, a PhD student at INSERM, University of Bordeaux, followed the participants for six years, the connection to dementia appeared strong. The interaction remained even after the scientists adjusted for potential confounding effect on Alzheimer’s rates such as blood pressure, heart disease, depression and insomnia.

In order to rule out the possibility that it was happening the other way around—that Alzheimer’s was causing a rise in insomnia and anxiety—the authors focused on people who had been prescribed sleeping and anxiety meds more than five years before they were diagnosed with Alzheimer’s. “We believe that the likelihood that the results are mainly driven by reverse causation is low,” de Gage said in an email discussion about the results.

It’s not clear why the drugs might increase the risk of Alzheimer’s, although de Gage speculates that the short-term effects on memory and cognitive functions may deplete reserve capacities that might help to offset reduce nerve functions as the disease’s hallmark protein plaques start to build up.

She also said that the study did not find an effect among those who used benzodiazepines for less than three months. That’s how most of the medications are prescribed, so people shouldn’t stop using them to treat anxiety disorders, social phobias and insomnia. But, she added, “It seems crucial to encourage physicians to carefully balance the benefits and risks when initiating or renewing a treatment [with benzodiazepines].”

TIME health

12 Unexpected Things That Mess With Your Memory

cigarette
Getty Images

You regularly ransack the house to find your keys. You suddenly can’t recall the name of your kid’s teacher. You made your six-month dentist appointment three months late. Sound familiar? Fear not: most forgetfulness isn’t anything serious, says Majid Fotuhi, MD, PhD, founder and chief medical officer of NeurExpand Brain Center in Luterville, MD and co-author of The Memory Cure. Lack of sleep, certain medications, and even stress can impact your memory. “Fortunately, your brain is malleable, meaning it changes and improves,” says Dr. Fotuhi. “Memory can be boosted with simple powerful interventions.” Here are surprising things that impact your memory in both good and not-so-good ways.

A dysfunctional thyroid

When your thyroid’s out of whack, you may feel too hot, too cold, anxious, depressed—and your memory may also be lagging. “Although the thyroid doesn’t have a specific role in the brain, memory loss is the one thing a person notices when it stops functioning normally,” says Dr. Fotuhi. A butterfly-shaped gland that sits along the front of your windpipe, the thyroid reigns over almost all your body’s metabolic processes. “People with high or low thyroid levels—which are very common in women—may have difficulty with memory and concentration,” he says. Ask your doctor for a simple thyroid test to determine if it’s the culprit behind your memory problems.

Health.com: 19 Signs Your Thyroid Isn’t Working Right

Hot flashes

Every time hot flashes make you you feel like sticking your head in the freezer, you may also feel a fog rolling into your brain. “The more hot flashes a woman experiences during menopause, the worse her ability to remember names and stories,” says Dr. Fotuhi. “Fortunately, hot flashes don’t damage the brain in any way. Memory improves once the hot flashes subside.” Other menopause-related symptoms contribute to memory loss, including insomnia and sleep apnea, Dr. Fotuhi says.

Lack of sleep

Last night’s late party makes it less likely you’ll remember your new coworker’s name the next day. “While some part of the brain takes a siesta when we sleep, deeper areas involved with memory and emotional response become relatively more active,” says Allen Towfigh, MD, medical director of New York Neurology & Sleep Medicine. “Individuals with sleep deprivation and sleep disorders not only suffer from impaired memory but also daytime fatigue, impaired attention, and reduced reaction time.” The standard recommendation of eight hours of sleep a night doesn’t necessarily work for everyone. If you wake up fatigued and fall asleep unintentionally during the day, then you may need more sleep, says Dr. Towfigh.

Health.com: How to Fake a Good Night’s Sleep

Anxiety and depression

Worrying about an upcoming presentation in front of the CEO may also hinder your memory, several studies show. “We don’t understand the exact link, but strong evidence indicates depression, anxiety, and bipolar disease disrupts the neural circuitry involved in developing and retrieving memories,” says Dr. Towfigh. “The severity of the memory loss often mirrors the severity of the mood disorder—severe depression brings about equally severe memory loss.” Prolonged periods of everyday stress increase cortisol levels in the brain, which causes our brain cells to lose synapses (the bridges that connect our brain cells to one another), and make it more difficult to create and retrieve memories. The good news is when memory loss exists with a mood disorder (including anxiety and depression), the memory loss is usually at least partially reversible. “As the individual’s mood improves, often so does the memory loss,” says Dr. Towfigh.

Prescription drugs

Check your medicine cabinet: many common prescription drugs can make you feel forgetful. Anxiety disorder meds like Xanax, Valium, and Ativan (which are benzodiazepines) put a damper on the part of the brain that moves events from the short-term to the long-term memory. Tricyclic antidepressants have a similar effect. Heart medicines including statins and beta blockers have also been linked to memory issues, as have narcotic painkillers, incontinence drugs, sleep aids, and even antihistamines like Benadryl. Bottom line: Don’t stop taking your (potentially life-saving) medications, but talk to your doc if you believe any drug you’re on may be messing with your memory.

Smoking

If you’re still smoking, that may help explain memory lapses. “Smoking damages the brain by impairing its blood supply,” says Dr. Towfigh. Research published in the Archives of General Psychiatry gathered from data obtained from more than 7,000 men and women found a more rapid decline in brain function (which included memory along with vocabulary and other brain functions) with age than from those who never smoked. “Furthermore, cigarette smoking promotes the accumulation of abnormal proteins which impair the brain’s ability to process and relay information,” says Dr. Towfigh.

Health.com: 15 Ways Smoking Ruins Your Looks

A high-fat diet

Greasy burgers and French fries pack on pounds and are hard on your heart—and they may also cause memory issues. One study revealed that adolescent mice had poorer learning and memory skills after being fed a high-fat diet for eight weeks, while another study on middle-aged rats found that the hippocampus (the part of the brain responsible for short-term memory) may be particularly vulnerable to the impact of high-fat diets.

More research is needed to determine for sure whether or not high-fat diets impact human memory, but here’s what we do know: Calorically dense diets promote type 2 diabetes, hypertension, and cardiovascular disease, which can all do damage to our brains, says Dr. Towfigh. “This holds true earlier in life, too. Studies link childhood obesity with a reduced attention span and impaired concentration and focus.”

Stress

A sudden emergency can make it tough to recall something as simple as your home address. A rat study published in Neuron shows that stress hormones influence an area of the brain area that controls working memory. Researchers found that repeated stress reduced receptors in the part of the brain that’s connected to thought processes Although this study involved animals, the human brain works similarly, explains Dr. Towfigh. “Repeated or chronic stress can be harmful. Regular exposure to elevated glucocorticoids (a hormone released by the adrenal gland) also causes our brain cells to reduce receptors, making brain cells less capable of responding to neurochemical (brain chemicals) cues.” Finding ways to relieve stress may help: Practicing meditation does double duty by easing stress and helping improve memory, according to a study from the University of California, Santa Barbara. College students who completed eight 45-minute meditation sessions over two weeks increased their average GRE exam scores from 460 to 520 and showed improvement on tests of working memory.

Health.com: 13 Ways to Beat Stress in 15 Minutes or Less

Germs

A nasty cold sore does more than make you feel self-conscious—it may be messing with your memory, according to a 2013 study in Neurology. Researchers found that people who exposed to many germs, such as herpes simplex type 1 (the cold sore virus), over their lifetimes were more likely to have memory problems than those exposed to fewer germs. Among more than 1,600 study participants, those with a higher “infectious burden” had a 25% increase in the risk of a low score on a cognitive test. Although there is no vaccine for the cold sore virus, childhood vaccinations against other viruses could help prevent problems later in life, the researchers suggest. In addition, regular exercise may help too—doctors think repeated infections may damage blood vessels, since a high infectious burden is also linked to a greater risk of stroke and heart attack.

Green tea

Now for some good news: chemicals found in green tea may help improve your memory, according to a University of Basel study. “Several compounds, EGCG and L-theanine, in green tea increase neurogenesis (growth of new brain cells) in the hippocampus, the part of the brain used for short-term memory and learning new things,” says Dr. Fotuhi. How much green tea has not yet been determined, says Dr. Fotuhi, who recommends combining green tea with other healthy habits such as exercise for greatest memory improvement benefits.

Exercise

Regular sweat sessions also help keep memories sharp. “Physical exercise improves mood and sleep and by doing so, it invariably improves cognition and memory,” says Dr. Towfigh. An animal study published in Brain, Behavior and Immunity, for example, showed daily exercise increased brain cell growth after 12 weeks of conditioned running. Dr. Fotuhi recommends 45 minutes of aerobic exercise four days a week for the best memory boost.

Health.com: 20 Tricks to Make Exercise an Everyday Habit

Vitamin B12 deficiency

Vegetarians and vegans are at a higher risk of being deficient in vitamin B12, which keeps the body’s nerve and blood cells healthy and helps make DNA. That’s because B12 occurs naturally only in animal foods: shellfish, meat, poultry, eggs, and dairy. In addition to fatigue, loss of appetite, constipation, and weight loss, a B12 deficiency can also lead to memory problems. If you feel your meatless diet may be affecting your memory, your doctor can give you a blood test that determines whether you should be taking a vitamin B12 supplement.

Note: it’s not just veggies who are at risk for a B12 deficiency. Pregnant women, older adults, and anyone with pernicious anemia or gastrointestinal disorders like celiac disease and Crohn’s disease may need supplementation.

This article originally appeared on Health.com.

TIME Mental Health/Psychology

You Asked: What’s the Best Bedtime?

Illustration by Peter Oumanski for TIME

The earlier the better? 11 PM? Sundown? Sleep experts say it’s not that simple. But there is a time range you should shoot for if you’re questing for a perfect night’s sleep

Every hour of sleep before midnight is worth two after midnight. Your grandparents (and great grandparents) probably adhered to that creaky adage. “The mythology is unfortunate, because there’s no pumpkin-like magic that occurs,” says Dr. Matt Walker, head of the Sleep and Neuroimaging Lab at the University of California, Berkeley. And while nothing special happens to you or the quality of your sleep at the stroke of midnight, many do wonder: What’s the best time to go to bed?

Walker says your sleep quality does change as the night wears on. “The time of night when you sleep makes a significant difference in terms of the structure and quality of your sleep,” he explains. Your slumber is composed of a series of 90-minute cycles during which your brain moves from deep, non-rapid eye movement (non-REM) sleep to REM sleep. “That 90-minute cycle is fairly stable throughout the night,” Walker explains. “But the ratio of non-REM to REM sleep changes.”

He says that non-REM sleep tends to dominate your slumber cycles in the early part of the night. But as the clock creeps toward daybreak, REM sleep muscles in. That’s significant, because some research has suggested that non-REM sleep is deeper and more restorative than lighter, dream-infused REM sleep—though Walker says both offer important benefits.

What does this have to do with the perfect bedtime? The shift from non-REM to REM sleep happens at certain times of the night regardless of when you go to bed, Walker says. So if you hit the sack very late—at, say, 3 AM—your sleep will tilt toward lighter, REM-heavy sleep. And that reduction in deep, restorative sleep may leave you groggy and blunt-minded the next day.

That’s unfortunate news for nightshift workers, bartenders, and others with unconventional sleep-wake routines, because they can’t sleep efficiently at odd hours of the day or night, Walker says. “The idea that you can learn to work at night and sleep during the day—you just can’t do that and be at your best.” Your brain and body’s circadian rhythms—which regulate everything from your sleeping patterns to your energy and hunger levels—tell your brain what kind of slumber to crave. And no matter how hard you try to reset or reschedule your circadian rhythms when it comes to bedtime, there’s just not much wiggle room. “These cycles have been established for hundreds of thousands of years,” Walker explains. “Thirty or 40 years of professional life aren’t going to change them.”

When it comes to bedtime, he says there’s a window of a several hours—roughly between 8 PM and 12 AM—during which your brain and body have the opportunity to get all the non-REM and REM shuteye they need to function optimally. And, believe it or not, your genetic makeup dictates whether you’re more comfortable going to bed earlier or later within that rough 8-to-midnight window, says Dr. Allison Siebern, associate director of the Insomnia & Behavioral Sleep Medicine Program at Stanford University.

“For people who are night owls, going to bed very early goes against their physiology,” Siebern explains. The same is true for “morning larks” who try to stay up late. For either type of person—as well as for the vast majority of sleepers who fall somewhere in between—the best bedtime is the hour of the evening when they feel most sleepy.

That means night owls shouldn’t try to force themselves to bed at 9 or 10 if they’re not tired. Of course, your work schedule or family life may dictate when you have to get up in the morning. But if you can find a way to match your sleep schedule to your biology—and get a full eight hours of Z’s—you’ll be better off, she adds.

Both she and Walker say your ideal bedtime will also change as you age. While small children tend to be most tired early in the evening, the opposite is true for college-aged adults who may be more comfortable going to bed around or after midnight. Beyond college, your best bedtime will likely creep earlier and earlier as you age, Walker says. And again, all of this is set by your biology.

Siebern suggests experimenting with different bedtimes and using sleepiness as your barometer for a best fit. Just make sure you’re rising at roughly the same time every morning—weekdays or weekends. It’s fine to sleep an extra hour on your days off. But if you’re getting up at 6:30 during the workweek and sleeping until 10 on weekends, you’re going to throw off your sleep rhythms and make bedtime more challenging, she says.

TIME Mental Health/Psychology

1 in 7 People Suffer From Being ‘Sleep Drunk’

Alarm clock
Getty Images

Severe disorientation while waking up or falling asleep could be a real problem

It’s a scene familiar to about 15% of us. Your alarm goes off in the morning, but instead of waking up alert (if not especially chipper), you’re entirely confused by what’s going on. You may be disoriented, not know where you are, and you may even try to answer your alarm as though it were a phone call.

If that’s happened to you, it’s because you’re sleep drunk.

According to a new report published in the journal Neurology, sleep drunkenness—which is having trouble coming to full wakefulness after sleep, accompanied by intense confusion and disorientation, and even sometimes violent reactions and amnesia—is a serious and surprisingly common problem.

Researchers at Stanford University School of Medicine interviewed 19,136 people ages 18 and older about their sleep behaviors, mental health, and medication use and found that about 15% of the participants had experienced a sleep drunkenness episode in the last year, with over half of those people reporting experiencing an episode a week. Further data suggests there may be a connection between sleep drunkenness and other factors, including mental health.

Among those who had reported sleep drunkenness episodes, 84% also had either a sleep disorder, a mental health disorder or were taking drugs like antidepressants, which suggests that sleep drunkenness could be a symptom of—or a red flag for—other problems that could disrupt sleep quality.

The researchers say that even though sleep-related problems like sleep drunkenness get less attention compared to behaviors like sleep walking, they can be just as dangerous, and more research should be done to determine the best ways to treat it.

TIME Research

School Should Start Later So Teens Can Sleep, Urge Doctors

The American Academy of Pediatricians (AAP) says there’s strong scientific evidence to support later school start times for middle and high schoolers

When it comes to the importance of sleep, it’s all about the biology, say pediatric experts. And in a report released Monday, the American Academy of Pediatrics supports pushing back start times for older kids, particularly teens, because it’s better for their mental and physical health.

“The evidence is clearly mounting both in terms of understanding the repercussions that chronic sleep loss has on the health, safety and performance of adolescents, and there is also really solid compelling data supporting the fact that delaying school start times is a very important intervention that can mitigate some of the impact of sleep loss,” says Dr. Judith Owens, director of sleep medicine at Children’s National Medical Center and lead author of the report.

In a statement published in the journal Pediatrics, the Academy’s Adolescent Sleep Working Group reviewed the studies to date involving how inadequate sleep among teens—which means anything less than 8.5 hours to nine hours a night on school days—can contribute to health issues such as obesity, diabetes, mood changes and behavior problems. They even analyzed studies linking poor sleep to increased reliance of substances like caffeine, tobacco and alcohol and the effect of sleep deprivation on academic performance. The evidence, they concluded, supports giving teens more time in bed by pushing back the time they have to be at school to at least 8:30am. Even a half-hour delay, some studies showed, can have dramatic effects on improving children’s health and academic performance.

MORE: The Most Well-Rested and Sleep-Deprived Cities in the World

The AAP committee studied the issue of adolescent sleep for nearly four years to come up with this policy statement, says Owens, and that data show that puberty may biologically wire teens to stay up late and wake up late—which means that forcing them to bed earlier won’t do much good. Something about the hormonal changes occurring during that period of development shifts their body clocks, which regulate the balance between sleeping and waking, later, like daylight savings in reverse. Puberty also pressures kids to stay up later because the normal sense of tiredness that builds up during the day is slower to develop among teens, so they can’t fall asleep earlier even if they wanted to. ”It doesn’t change how much sleep they need, but it makes it easier for them to stay awake longer,” says Dr. Mary Carskadon, a professor of psychiatry and human behavior at Brown University Medical School and director of sleep and chronobiology at Bradley Hospital.

That’s why delaying school start times may make more sense than enforcing earlier bedtimes. According to a 2006 National Sleep Foundation poll, 87% of high school students don’t get the recommended 9 to 10 hours of sleep they need to function at their best and promote healthy mental and physical development; most average around seven hours of sleep on weeknights. And the effects of that deprivation may show up in their grades; about 30% of students report falling asleep in class at least once a week, and studies consistently connect less sleep with lower grades in school and on standardized tests. Students who don’t get the recommended amount of sleep also tend to have higher rates of anxiety and mood disorders, including depressive symptoms.

But in the 70 school districts involving more than 1,000 schools that have adopted later start times for high school students, teachers, parents and the students themselves are seeing substantial benefits. In one district that pushed back start times by one hour, half of the students reported getting eight or more hours of sleep, compared to 37% who had prior to the shift.

MORE: Less Sleep Pushes Your Brain to Age Faster

Owens and her colleagues also conducted a study among students at an independent school that delayed start times by 30 minutes. That was enough to shift bed times earlier, by an average of 18 minutes, something that surprised her and her team. They also found that the delay increased the percentage of students getting eight or more hours of sleep a night. “Anecdotally, a lot of the students said they felt better with the extra half hour of sleep they got in the morning, and that motivated them to go to bed earlier as well,” she says. “They said they could focus better and concentrate better and that it took them less time to get their homework finished so they could go to bed earlier.”

None of the studies show that delaying school start times encourages students to go to bed even later, a concern that some parents and health care workers have raised about the policy.

Having high school students start later may also have domino effects on everything from their extra curricular activities, including sports, which often occur after school, and on child care issues for parents who rely on older children to take care of their younger siblings following school. “Communities and school districts really need to go all in and make a commitment [to it],” says Carskadon. “Where it doesn’t work is where schools just dabble and say they will try it for six months to see how it works.” Adds Dr. Cora Breuner, professor of pediatrics and adolescent medicine at Seattle Children’s Hospital at University of Washington and a member of the committee, “we know that implementation of our recommendations wild be challenging but we stand behind these recommendations and strongly ask that they be considered for the health of our children.”

MORE: Poor Sleep Affects Babies’ Weight Later In Life

And in some districts, efforts to overcome the hurdles are starting to work. Some schools, for example, have created after-school programs where younger children can remain at school in a supervised setting until their older siblings or parents can take them home. And in communities in Minnesota and Massachusetts, where elementary school students are starting school earlier to accommodate bus service for the older students later, community volunteers have manned the stops to ensure younger children are safe while they are waiting to be picked up during early morning hours.

“The hope is that this statement will galvanize communities,” says Carskadon. “Now they have another tool in their tool kit, and another set of evidence and advice to take to school committees and school boards, to get communities moving on addressing adolescent sleep.” Given the state of the data on how poor sleep affects adolescent development, adds Owens, “to do nothing Is really to do harm. The status quo of starting schools at 7:15 or 7:20 is not in the best interest of the students.”

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