I hear the
floorboards creak, the toilet flush, first one shoe drop to the floor, then the
other. My husband pulls back the covers and climbs into bed, disturbing
the dog, who now spins around rattling her tags looking for a new, cozy den.
I groan and turn over to look at the clock: 3 a.m., an early night for
him. You see, my husband is what many people call a "night
owl," but really he suffers from a circadian rhythm sleep disorder called delayed sleep
phase disorder.
Circadian rhythm means
a 24-hour cycle. Humans have a 24-hour sleep/wake cycle that is linked to
the 24-hour cycle of the sun. So, in the optimal situation, we rise in
the morning and after about 16 hours of wakefulness we are sleepy and we go to
bed and sleep for eight hours. In my last blog, I talked about shift work
disorderand how shift workers are not able, because of their
jobs, to flow with this natural rhythm.
People with
delayed sleep phase disorder also get out of sync with what we would consider
normal bed times (10 p.m. to midnight), but for unknown reasons. The exact
prevalence in the general population is unknown, but it is estimated to affect
7 percent to 16 percent of teens and young adults.
Delayed sleep
phase disorder usually begins in adolescence or early adulthood. Sleep
onset is delayed at least two hours from social norms, and these altered
sleep/wake times can impair the work, academic and social parts of sufferers'
lives.
People with DSPD
often complain of insomnia because they try to go to sleep at a normal time but
their internal rhythm is set to a later time and sleep is usually impossible
until very late. Then, if they have to get up for work or school, they
are very tired and sleepy in the daytime and are not functioning at their highest
capabilities. Often, they will steal a nap, but that only sets them up for
further delay in their bedtime.
Usually the
patients who show up at the sleep center are teens who are brought in by their
mothers because they can't get up and make it to their early morning classes.
Their grades are failing and the school is threatening to expel them. How
do I help them? Well, I must return to my near-constant theme:
Light.
We get them on a
schedule where we slowly move up their bedtimes - just 15-30 minutes each time
over a series of weeks. With each change in bedtime, they are instructed to be
sure to avoid bright light two hours before the desired bedtime. We often
need to use glasses that filter the blue light because it is not realistic to
think that teenagers are not going to be on the computer or using some
electronic device.
I also have them
get outside and get some bright light in the mornings. Where I am in
Chicago, for much of the year we recommend that such patients use light boxes
in the morning. I recommend the ones made by Lite Book because they use LED
technology, which means they are smaller and patients need to spend only
15-30 minutes in front of the unit.
We also use melatonin,
but not as a sleep aid. Instead, we use it to alter people's circadian
rhythm, and therefore, we give it 5-7 hours before desired bedtime and we use
small doses (0.5-1.0 mg). And I always recommend that they try this at
home the first few times in case it makes them sleepy right away.
I would like to
caution that although this general principle of bright light in the morning and
dim light before bedtime is easy enough to understand, it is also easy to apply
the principle incorrectly and actually make matters worse. For example, a
well-meaning mother of a 16-year-old reads this and tomorrow morning hauls her
son out of bed at 6:30 a.m. to get him to his first AP class. The next
night, to her dismay, he stays up even later, and getting him up the following
morning would require inviting the marching band to hold practice in his
bedroom.
What has gone
wrong? Well, when mom got him up at 6:30 a.m., he had only had 4½ hours
of sleep and his core body temperature had not reached its low point.
When his eyes received bright light before the lowest drop in core body
temperature, then the internal clock in the brain was being reset to a later
time and actually delaying the sleep onset for the next night. Many times we
have to wait until a vacation to try to reset someone's clock. Most
times, the help of a sleep physician is essential, and always, the patients
themselves have to want to change their schedule.
Another word of
caution: It is easy to confuse this disorder with insomnia,
but just giving the young person a sleeping pill doesn't usually work to reset
the internal clock.
Why do some teens
have these dramatic shifts in sleep onset and not others? This can run in
families and changes in one of the circadian clock genes have been associated
with this disorder but we cannot yet point to a specific genetic mutation that
causes this problem. Delayed sleep phase can be associated with depressive
symptoms but the good news is: Many will naturally outgrow it, especially
when the responsibilities of adult life force them into becoming morning
people. Some, like my husband, will return to their nocturnal ways every
chance they get.
Lisa Shives,
M.D., is the founder of Northshore Sleep
Medicine in Evanston, Illinois. She’ll blog on Tuesdays on The Chart. Read more
from her at Dr. Lisa Shives’ Sleep Better Blog.
The
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based on the information that is presented here. Please consult a physician or
medical professional for personal medical advice or treatment.
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