Set Your Body Clock for Better Sleep

By John F. Greden, MD | Depressions and sleep problems often go hand in hand. Establishing a strict daily routine will help reset the body’s “master clock” and improve your rest.

Problems with sleep are such a common symptom in depressions that it appears to be innate. Maybe a third of people with depression sleep too much (hypersomnia). Others have trouble with falling asleep, waking in the night, or early waking in the morning (forms of insomnia).

Why are my sleep patterns so bad?

Sleep irregularities typically trace back to stutters in the body’s circadian rhythms—the natural daily patterns of when we wake up, when we’re ready to sleep, when we’re most alert, when we get hungry, and so on.

Circadian rhythms run according to an internal body clock. Actually, we have biological clocks in every cell in our bodies. A “master clock” in our brain keeps the orchestra in time and working together.

For whatever reason, people with mood disorders tend to have irregularities in their master clock, probably due to the influence of what are known as clock genes and downstream effects on brain and molecular neurotransmitters.

The body clock can also be disrupted by social demands and behavioral choices. If you travel, if you have shift work, if you’re getting up with an infant at night, if you watch Netflix until 3 a.m., if you drink alcohol or caffeinated drinks—each has the potential to force the clock to reset itself.

For most of us, the biological clock doesn’t reset quickly. If you travel across several time zones, it can take as long as a week to 10 days.

How can I reset my body clock for better sleep?

The biological clock can be strengthened or reset by adhering to structured daily routines. That’s because of how it responds to cues called zeitgebers (the German word for timer).

The most powerful zeitgeber that’s been identified is light, which travels through the retina and sends direct signals to the master clock in the brain—technically, the suprachiasmatic nucleus in the hypothalamus.

Thus the shorter days of winter often result in less energy and a desire to sleep more. For people who are especially sensitive, gloomy weather equals gloomy mood. Shifts in light or too little light can set off depressions in those who are vulnerable.

Artificial lighting allows us to continue our activities after sunset, but exposure to bright light in the evening affects the surge and ebb of neurotransmitters— melatonin, serotonin, norepinephrine and others—that affect how sleepy or alert we feel.

That’s why sleep experts urge against using “blue screen” devices such as smartphones and laptops in the hour or two before bedtime. In fact, the power of the light zeitgeber is such that turning on the light to go to the bathroom at night makes it harder for many of us to fall back asleep.

Light in the red-orange spectrum doesn’t have the same effect. It’s best to use a 25-watt red bulb as a night-light in the bathroom or in a child’s bedroom if you’re getting up for feedings.

Reducing ambient light in the house as bedtime approaches also helps. Turn off unneeded light fixtures and use lower-watt bulbs or dimmers in the ones that stay on.

Social cues also help us wake up and stay on schedule throughout the day. Your alarm clock is a zeitgeber.

Start by anchoring your daily routine to a consistent wake time, even on weekends. Count backwards to establish a consistent bedtime—and again, stick to that as closely as other demands in your life allow.

The timing of food consumption has been shown to affect circadian rhythms. Try to eat meals at the same time every day. Ditto for meditation, exercise and the like. If you schedule your own work, whether it’s paid or volunteer or housework, block out regular hours. Keeping a daily “time diary” often helps with reinforcing your routines.

Printed by Esperanza as “Ask the doctor: Set your body clock for better sleep,” Winter 2019