How to Get the Best Rest

In psychiatry and medicine in general, sleep should be considered a vital sign. Almost every psychiatric condition, whether anxiety or bipolar disorder, ADHD or dementia, is substantially affected by lack of quality sleep. Poor sleep undermines impulse control, making us “bingey,” settling for quick fixes over more meaningful goals; harder stuff takes perseverance and discipline—that is, impulse control. More than a decade of work as a psychiatrist and sleep medicine specialist has taught me that helping people sleep better is most of the cure.

Sleep has a cyclical structure that repeats about every 90 minutes during the night. Stages 1 and 2 are light sleep, followed by Stage 3, or slow-wave, sleep, and, last, REM, or dream, sleep. Notably, slow-wave sleep occurs predominantly in the first half of the night, dream sleep more in the morning hours. Slow-wave and REM sleep each take up about 20 percent of the night.

Early in the night, as you enter deep sleep, brain and metabolism slow, and it’s hard to wake up. If you do wake, you’re slow and confused. During deep sleep, the brain does massive maintenance work, cleaning out the by-products of a day’s worth of thinking. Among these are two proteins, tau and beta-amyloid, accumulations of which are seen in brain cells of people with Alzheimer’s disease. Lack of deep sleep is associated with earlier-onset dementia. In my practice, improving people’s deep sleep has slowed, even reversed, cognitive decline. Not many interventions can make that claim.

Deep sleep is also essential for memory formation and processing. The more you think or learn by day, the more deep sleep you need that night. Your brain moves memories from temporary to permanent storage and clears space for new information. People asked to remember pairs of words remember more in the morning if they got more deep sleep at night. (Be sure to sleep well before tests of memory!)

Spatial memory—required for navigating about town or remembering where you put the car keys— is also linked to slow-wave sleep. Notably, a loss of spatial orientation is an early symptom of dementia. Since normal aging is associated with a decrease in slow-wave sleep at night, do everything you can to get it while you can. Deep sleep also renews metabolism, restoring insulin sensitivity to provide energy, and it boosts immune function.

After the first period of deep sleep, usually 90 minutes after falling asleep, the brain enters REM sleep. Cycles of REM are short at first and lengthen toward morning. Think of REM sleep as the ultimate virtual reality experience. You’re basically awake—brain waves mimic those of wakefulness—but the body is paralyzed so you don’t act out your dreams. It’s easiest to wake during REM sleep.

In REM sleep, the brain is totally active, albeit internally. Heart rates and breathing rates vary as we go through the internal experience of our dreams. Men can get an erection. The body will hit a temperature low for the entire day. While most muscles are paralyzed, airway muscles can become softer, leading to sleep apnea.

During REM sleep, the brain rehearses procedural memories like swimming or swinging a tennis racket. That’s why getting good sleep boosts physical performance. What’s more, the brain gets a large dose of psychotherapy. We replay and process emotional memories, make sense of daily emotional experiences, and simulate future situations and interactions.

REM sleep is also a source of human creativity. Imaging studies show the brain testing out new connections during REM sleep, which is why dreams can feel random, emotional, even outlandish. Yes, people score higher on creativity tests following more REM sleep. Research comparing the brain of people on psychedelic agents and during REM sleep shows similarities—explaining, perhaps, why both are associated with creativity.

Sleep is essential for thinking and feeling well. People deprived of sleep tend to be more impulsive. Internally, impulse control helps you harness runaway thoughts of anger, anxiety, and sadness. Moods are more intense and tempers shorter after a night of poor sleep. The ability to control impulses resides in the prefrontal cortex, the most advanced part of the brain and the first to go offline when we’re sleep-deprived.

You won’t die tomorrow from lack of sleep. But as with poor diet or lack of exercise, the effects add up over time, creating risk of obesity, diabetes, hypertension, heart attack, and stroke. Most mildly sleep-deprived people fail to recognize that they’ve got a problem, so they continue to get insufficient sleep.

Electric lights and electronic devices have made sleep a last priority. As fatigue builds during the day, willpower, rooted in impulse control, dwindles: We snack on unhealthy things, drink alcohol, and use drugs more in the evening. It’s also why it’s hard to put down your phone or stop bingeing on your favorite show as the hours advance— making you more tired tomorrow.

Adults need seven to eight hours of sleep per night. Human nature being what it is, if you aim for eight, you’re likely to get seven. It’s best brought on by a winding-down routine—slowing down, dimming lights, and putting down phones. Sleep loves rhythm, so regular bed and wake times are essential, without much drift on the weekends. Earlier to bed tends to boost slow-wave sleep. Getting enough sleep overall tends to boost REM sleep.

There’s one more thing that good sleep needs: silence. Unfortunately, digital technology has ended boredom, which previously afforded time to think about a conversation we had, an upcoming meeting, or future plans. That thinking needs to happen sometime, and the only time our brains have left to freely roam now is before we fall asleep. That’s a recipe for insomnia.
If you want to sleep better at night, give yourself a chance to think earlier in the day. Stare more. Distract yourself less. A meditation practice can be a great cure for insomnia. More silence in your day will deliver better nights.

How to Improve Deep Sleep

1. Get more sleep; it’s best to align sleep hours with your natural sleep pattern.
2. Boost sleep quality, allowing sufficient slow-down time before bed.
3. Supplements may be helpful in attaining and sustaining deep sleep. Supplements to consider include melatonin, L-theanine, glycine, and magnesium.

Alex Dimitriu, M.D., is the founder of Menlo Park Psychiatry and Sleep Medicine.

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