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Soyon Jun / Senior Staff Photographer

Here we see a college student getting a rare moment of shut-eye.

MASTERPIECES OF WESTERN SLEEP: 0 pts. Enrollment unlimited. Attendance at all class periods is mandatory. Focused survey of a set of problems experienced by an undetermined number of undergraduate and graduate students, junior and senior faculty, alumni, administration, security and maintenance personnel. Topics include: screwed-up sleep, delayed circadian rhythms, and their effects on performance, concentration, mood, vigor, and immune system status. Discusses and guides validated non-medication therapies such as scheduled light exposure, darkness, and synthetic melatonin, based on empirical results of controlled clinical trials. Offered M-F, 1 a.m., at the West End.

The field of sleep medicine, some 30 years old, has largely focused on disorders and their treatments. This effort has been momentous, as anyone who has dealt with a sleep problem will gratefully agree. But what is needed in addition is a positive frame of reference that gives us a way to know how well we are doing. Just because you don't have a disorder doesn't mean sleep is doing its job for you. The latest insight from researchers is that sleep enables a cleansing process, which rids the brain of toxic waste that builds up during the waking day, including beta-amyloid proteins associated with Alzheimer's plaques. The new emphasis is on sleep health, which optimizes daytime functioning.

You're in the majority if you don't rate “Usually/Always” across the board. In other words, there's room for improvement that can have major, satisfying consequences, even if it means rearranging your schedule. By rearranging, I don't mean by force of will—that's unlikely to succeed. I'm referring to chronotherapy, whose goal is to match circadian rhythm with time in bed. The misalignment of the two is a formula for non-restorative sleep, depressed mood, and daytime fatigue. We can now hypothesize, on the basis of the latest research, that this results from incomplete elimination of toxic wastes.

I asked Dr. Mary O'Brien, my colleague at Columbia Health Services, how she appraises sleep health in students she sees, whether or not sleep is their primary complaint. 

She observes, “Sleep problems are a significant issue for our students. Here are common responses from my patients when I ask about their sleep: 

• I only have time to sleep five to six hours per night.

• I have no regular sleep schedule.

• I go to bed later and later, and now I can't fall asleep before 4 a.m., and then I sleep until noon. 

• I have a hard time falling asleep because my mind is active, worrying, or thinking about my work.

For almost all students, lack of sunlight is common, especially in the winter. Many of my depressed patients have substantial sleep problems.”

Optimum sleep involves the joint action of two independent brain processes. We want them to be in sync. Sleep pressure is the first, which begins as soon as we wake up. Our bodies create a need (thought to be mediated by the neurotransmitter adenosine) to sleep again. The pressure recedes once we go back to sleep. 

The second process is the circadian cycle of body functions, which rise and fall across the 24-hour day, controlled by neural and humoral output signals from the inner clock. This timing system is built genetically to cycle somewhat longer than 24 hours in most people. The physiological challenge is to reset the inner clock each day, so it matches the solar cycle. Adolescents and young adults are most likely to experience circadian rhythms that drift away from nighttime sleep because puberty comes with a slowing of the circadian clock, which delays signals for sleepiness and wakefulness. When sleep pressure and the circadian cycle reinforce each other, the result is healthy sleep. The more they come into conflict, the more our sleep health declines.

The good news is that both sleep pressure and the circadian cycle can be brought under control with self-administered chronotherapeutic techniques. Setting a regular wake-up time helps ensure that sleep pressure builds to its high point at bedtime. As for the circadian cycle, exposure to bright light during the hours shortly before bedtime can overwhelm the sleep signal and make it harder to fall asleep. By limiting light exposure, particularly light from the bluish part of the spectrum, this interference can be avoided. Wearing blue-filtering lenses during the evening hours while on the computer or using f.lux, an app that subtracts blue pixels from the screen, are two simple but effective steps. 

The principal technique of chronotherapy is bright light exposure as soon as you wake up. A retinal signal communicates with the inner clock—speeding it up, counteracting its delay tendency, and synchronizing it with sleep. Bright light boxes are the simplest way to provide a consistent, daily “entraining” signal, especially in late fall and winter, when most people have to start their days when light is low in the sky. Without this light, the inner clock drifts later, out of synchrony with habitual sleep time; wake-up is arduous, and alertness comes only at midday.

The sacrifices in bringing the system into sync are trivial, in my opinion. A satisfying social life doesn't require partying after midnight. And with early-morning alertness, nighttime study can be shifted to the morning and be more effective.

The author is a Columbia College graduate from the class of 1964. He is a professor of clinical psychology in psychiatry at Columbia University Medical Center, and the author of Reset Your Inner Clock. He is the founder of the Comprehensive Chronotherapy Group, a clinical consortium for circadian rhythm disorders. After Office Hours runs every Friday.

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