For the past several months I’ve been focusing on achieving better sleep. It’s my hypothesis that my mental problems are mostly sleep-related. I’ve done some reading on the subject, and some experimentation, and want to share what I’ve learned.

In the marvelous The Owner’s Manual for the Brain, Pierce J. Howard summarizes sleep research with the following lists:

To get to sleep more quickly:

• Consume dairy products (the warmer the better).
• Avoid artificial sweeteners.
• Avoid food additives.
• Avoid caffeine within six hours of bedtime.
• Keep to a regular bedtime.
• Consume carbohydrates an fats; avoid protein.
• Read or view unexciting material.
• Avoid exercise within four hours of bedtime.
• Sleep in absolute darkness and complete silence.
• Take melatonin.

To get better quality sleep:

• Lose weight.
• Avoid alcohol within four hours of bedtime.
• Drink water after alcohol consumption.
• Plan sleep according to sleep cycles and circadian rhythms.
• Do aerobic exercise regularly, but not close to bedtime.

To get back to sleep after waking:

• Write down what’s on your mind.
• Read something unexciting.
• Drink warm milk and honey.

Some of these concepts are worthy of further discussion. (Note: while most of what follows is in my own words, some sentences are lifted verbatim from Howard’s book.)

The Sleep Cycle

It’s not the length of sleep that is important, but the number of complete sleep cycles a person obtains. Each sleep cycle has several stages, the most important of which is REM sleep (during which dreams occur). On average, a complete sleep cycle lasts around ninety minutes. (This varies from person-to-person and from night-to-night, but ninety minutes is a close average.)

I first became aware of the sleep cycle phenomenon soon after I began taking melatonin. I noticed that I was waking at approximately ninety minute intervals. “That’s odd,” I thought. I began to make predictions. When I found myself awake at 1:05 I’d say to myself, “I will next wake at 2:35.” When I woke at 2:38 I’d say to myself, “I will next wake at 4:08.” When I woke at 4:07 I’d say to myself, “I’ll wake at 5:30, with my alarm.” What was truly odd was that these predictions were accurate nearly every time: ninety percent of the time, I was waking at ninety minute intervals. I concluded that my sleep cycle was approximately ninety minutes in length.

Research has shown that how well-rested a person feels is directly related to the number of complete sleep cycles she obtains. A person who completes five sleep cycles on a given night will feel better rested than a person who completes four sleep cycles. The trouble with certain sleep disorders — such as sleep apnea — is that they limit the number of sleep cycles one achieves.

When you’ve determined the length of your sleep cycle, you can make some important adjustments. For example, since my sleep cycle averages ninety minutes, and since I get up at 5:30, I know to go to bed at 10:00, giving me seven-and-a-half hours of sleep. If, as last night, I miss my ten o’clock bedtime, I know that it makes no difference whether I go to bed at 10:30 or 11:30 — both times would offer me the same number of complete sleep cycles. Thus, I stayed up an extra hour reading.

Actually, there’s strong indication that waking at the end of a sleep cycle muddles the mind; it’s better to wake at the beginning of a sleep cycle than to wake in the middle of REM sleep (the middle of a dream). Last night, I’d probably have been better served having gone to bed at 11:15, just in case I had trouble falling asleep, and just in case my sleep cycle had been misaligned so that I’d awakened during a dream.

The Circadian Rhythm

Scientists have known for a long time that humans have a built-in twenty-five hour body clock. I’m not sure anyone has developed a satisfactory explanation for why this is the case, but it is. This explains why it’s so easy for most of us to stay up late.

As part of our natural circadian rhythm, various body chemistry changes occur throughout the day, affecting us in different ways.

During the morning, rote memory is at its best. The mind is quick and nimble. During the afternoon, the body is at its physical peak. (Though there is a dip in the mid-afternoon.) In the evening, both the body and mind begin to relax. During the night, whether we’re sleeping or awake, the body and mind exhibit signs of near-dormancy.

What does this mean? If you have important mental work to do, it’s best to do it in the morning. If you have important physical work to do, it’s best to do it in the afternoon. If you’re cramming for a test, it’s better to stay up late than it is to get up early (before 6am) to study; your mind and body are at their lowest between 3am and 6am, regardless of whether you just woke from sleep.

Take naps. Based on the average circadian rhythm, the ideal time for a nap is between noon and 3pm. The ideal length for a nap is about thirty minutes. The urge to nap is natural; resisting the urge has a negative effect on health, productivity, and well-being.

Other Thoughts

Caffeine While afternoon and evening caffeine consumption can cause sleeplessness for me, it’s interesting to note that if I drink caffeine within thirty minutes of going to bed, it doesn’t prevent sleep. Instead, it enhances my REM state, giving me wild, memorable dreams. Your mileage may vary.

Melatonin I’ve been using melatonin now for several months. I buy it in 3mg pills. Often I use a pill-splitter to produce 1.5mg doses. I find that a 3mg dose can sometimes produce residual sleepiness in the morning. Whatever the dose, melatonin works wonders for me. When I take it, I fall asleep more quickly and I sleep more soundly. Give melatonin a try if you have sleep trouble — it’s available at your local supermarket.

CPAP machine I’ve had my CPAP machine for six weeks now. I’ve used it every night. Though the change in my sleep has not been drastic, I am beginning to detect subtle changes. It used to be that I woke several times each night to go to the bathroom, or to sit and stare at the ceiling; now — except in rare cases — I sleep through the entire night without waking. I used to feel sleepy all the time, to such an extent that driving was sometimes dangerous; now I generally feel well-rested (though not peppy), and have only occasional bad days during which I always want to sleep. I’m sad that the sleep changes with the CPAP machine haven’t been dramatic, but am happy that it’s helping me overall.

I’m sure to have missed some important points here. (For example, Jeff’s advice on Breathe Right nasal strips for better sleep.) I’ll try to post more advice when I remember it.