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Q: |
What is Seasonal Affective Disorder
(SAD)? Everyone gets "the winter
blues" - what's different about
SAD? |
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A: |
Many people complain of feeling
down, having less energy, putting
on a few pounds, and having difficulty
getting up in the morning throughout
the dark, short days of winter.
People suffering from SAD experience
these and other symptoms to such
a degree that they feel unable to
function normally. They often feel
chronically depressed and fatigued,
and want to withdraw from the world
and to avoid social contacts. They
become less productive at work and
complain that their quality of life
has gone. In the extreme, they may
increase their sleep by as much
as four hours or more per day, have
greatly increased appetite - sometimes
accompanied by irresistible cravings
for sweet and starchy foods - and
gain a substantial amount of weight.
Women frequently report worsening
of premenstrual symptoms. People
with SAD suffer in the extreme the
kinds of changes that many others
experience to a much lesser degree
in wintertime.
An individual SAD sufferer, however,
need not show all the symptoms described
above. Sleep duration, for example,
may be normal while carbohydrate
craving may be extreme - or vice
versa. Sometimes a symptom in the
cluster is actually opposite the
norm, such as insomnia as opposed
to excessive sleep. A proper diagnosis
of SAD requires a professional evaluation
by a psychiatrist, psychologist
or social worker. Although people
with SAD often diagnose themselves
correctly, professional confirmation
is very important because certain
medical conditions can be misdiagnosed
as SAD, and because people can become
depressed for many reasons aside
from changes in their physical environment.
Recent studies indicate that about
three times as many people suffer
from "winter doldrums",
a sub-clinical level of SAD, as
suffer at a level of clinical severity.
These people notice the return of
SAD-like symptoms each winter and
are bothered by them, but remain
fully functional. As much as 25
percent of the population at the
middle-to-northern latitudes of
the United States experience "winter
doldrums". |
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Q: |
What is light therapy for winter
symptoms, and how is it delivered?
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A: |
Light therapy involves exposure
to intense light under specified
conditions. The recommended light
therapy system consists of a set
of fluorescent bulbs installed in
a box with a plastic diffusing screen,
and set up on a table or desk top
at which one can sit comfortably
for the treatment session. Treatment
consists simply of sitting close
to the light box, with lights on
and eyes open. Looking at the lights
is not necessary or recommended;
rather, one is free to engage in
such activities as reading and writing,
or eating meals. What is important
is to orient the head and body toward
the lights, concentrating on activities
on the surfaces illuminated by the
lights, and not on the lights themselves.
Treatment sessions can last from
15 minutes to 2 hours, usually once
a day, but sometimes split into
separate sessions, depending on
individual needs and equipment used.
The amount of light reaching the
eyes and the duration of light treatments
may need to be adjusted to achieve
the best possible effect. It may
be possible to shorten the duration
of exposure by using a light source
that gives off more light, or by
sitting closer to the lights. It
is important, however, to stay within
the recommended guidelines that
come with the lighting system.
Early research used special "full-spectrum"
bulbs producing light similar in
color composition to outdoor daylight,
but more recent devices have used
ordinary fluorescent bulbs (cool
white, warm white, and triphosphor
types) with similar results. (Since
full-spectrum bulbs are designed
to include ultraviolet light, which
might contribute to cataract formation
and skin problems, it is best to
avoid such light at high intensity
unless it has been carefully filtered
for UV.) What appears to be critical
is that the level of light produced
match that of visible light outdoors
shortly after sunrise or before
sunset. Light intensity is critical
for adequate therapy. Systems deliver
varying amounts of light, which
should be specified in detail by
the manufacturer, with information
provided as to how far away the
patient should sit in order to receive
the rated intensity.
Two recent innovations in apparatus
design are worth noting. One is
a head-mounted lighting unit that
allows the user to move around while
taking the treatment. Extensive
testing of one such unit, however,
was inconclusive. Although users
reported feeling less depressed,
it is not clear that this was more
than a placebo effect. In principle,
there is no reason why head-mounted
units should not work effectively,
provided that sufficient light gets
to the eye. Further research and
design enhancements may be needed
to clarify the potential of this
method.
A second type of innovation has
been the design of dawn/dusk generators
which present graduated light signals
in the bedroom as substitutes for
(or as supplements to) bright light
exposure. Although it is too soon
to make a strong conclusion about
clinical effectiveness because of
the small number of studies, the
use of simulated dawn signals appears
to be antidepressant. Nonetheless,
additional research is needed before
a recommendation can be made.. |
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Q: |
Is increased exposure to
normal room light therapeutic, without
the use of special apparatus?
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A: |
For many people with winter depression,
and especially those with the milder
'doldrums', it can be helpful to
increase the amount of indoor lighting
with regular lamps. This is also
true for people who live or work
in dim environments. However, research
studies show that most sufferers
of SAD and winter doldrums require
exposure to much higher light levels.
Such therapeutic levels are usually
at least five times higher (as measured
in lux or foot-candles by a light
meter) than provided by ordinary
indoor lamps and ceiling fixtures
in the home or office. |
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Q: |
If outdoor light intensities
are what's critical, can the therapeutic
effect be achieved by spending more
time outdoors in winter? Does this
depend on the timing or the light?
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A: |
Some people report improvement by
spending more time outdoors, where
light intensity (even when it is
overcast) can far exceed that of
indoor light. For some, however,
it appears that the strongest therapeutic
effect requires exposure to artificial
bright light in early morning at
an hour (6:30 a.m., for example)
when it is still quite dark outdoors
during long winter nights. For others,
however, the time of day of treatment
doesn't seem to make a difference,
and afternoon or evening light may
also work. (Light taken very shortly
before bedtime, however, may cause
insomnia.) Those people who can
sleep later on winter mornings may
benefit by outdoor light exposure
after awakening. Although just going
outside may be adequate (weather
permitting), looking directly at
the sun must be avoided as it could
cause eye damage. |
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Q: |
Do the lights really work?
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A: |
Researchers at medical centers and
clinics in the U.S., Canada, Europe,
Asian and Australia have had much
success with light therapy in many
thousands of patients with clear
histories of SAD for at least several
years. Marked improvement is usually
observed within four or five days,
if not sooner, and symptoms often
return in about the same amount
of time when the lights are withdrawn.
Some people take longer than the
usual few days to respond to light.
It is therefore worth persevering
for a week or two before concluding
that light therapy doesn't work.
Most users maintain a consistent
daily schedule of light exposures
beginning -as needed - in fall or
winter and usually continuing until
spring, when outdoor light becomes
sufficient to maintain good mood
and high energy. Some people can
skip treatments for one to three
days, occasionally longer, without
ill effect, but most start to slump
quickly when treatment is interrupted. |
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| Q: |
How
do the lights work? |
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| A: |
The
therapeutic level of illumination
has several known physiological
effects, though its mechanism of
effect is still unclear. Blood levels
of the hormone melatonin, which
may be abnormally high at certain
times of day, are rapidly reduced
by light exposure. Depending on
when bright light is presented,
the body's internal clock - which
controls daily rhythms of body temperature,
hormone secretions, and sleep patterns
- shifts ahead or is delayed when
stimulated by light. These physiological
time shifts may be the basis of
the therapeutic response. On the
other hand, the antidepressant effect
may not involve rhythm shifts, but
rather overall changes in neurotransmitter
(chemicals involved in the communication
between brain cells) activity. Neurotransmitters
such as serotonin and dopamine may
be prime candidates. Research into
possible mechanisms is currently
underway, and the final answer is
not yet in. |
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| Q: |
Are
there any side effects? |
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| A: |
Side
effects have been minimal. People
occasionally report eye irritation
and redness that can be alleviated
by sitting farther from the lights
or for shorter periods. Using a
humidifier to counteract the dryness
of winter air indoors may also help.
A few people have reported feeling
mildly nauseous or agitated when
beginning light treatment; this
tends to pass quickly as one accommodates
to the high intensity. The most
dramatic side effect, and one that
occurs infrequently, is a switch
from the lethargic state to an over-active
state in which one may have difficulty
getting a normal amount of sleep,
become restless - even reckless
- and be unable to slow down, feel
irritable, or subjectively speedy
and "too high". This state is called
hypomania, when milder, and mania
when more severe. People who have
previously experienced these states
in late spring or summer are particularly
vulnerable. In such cases, the guidance
of a clinician skilled in the use
of light therapy is important. For
example, the dose of light should
be reduced, and other treatments
may be required. |
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| Q: |
Can
the lights be combined with antidepressant
medication? |
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| A: |
Patients who have received partial
benefit from antidepressants often
begin light therapy without changing
drug dose. If there is quick improvement,
it is then sometimes possible to
withdraw the drugs (or reduce drug
dose) under clinical supervision,
while maintaining improved mood
and energy. Some patients find a
combination of light and drug treatment
to be most effective. Some antidepressant
drugs (as well as lithium, St. John's
Wort, and melatonin), however, are
known or suspected to be "photosensitizers",
i.e., they may interact with the
effect of light in the retina of
the eyes. Users of antidepressant
or other drugs should therefore
check with their physician or ophthalmologist
(eye specialist) before commencing
light treatment. |
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| Q: |
When
should the lights not be used? |
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| A: |
No adverse effects of light therapy
have been found in ophthalmological
(eye) examinations of SAD patients
after treatment, but caution is
warranted in people with pre-existing
eye disease. There are several conditions
(such as macular degeneration, retinitis
pigmentosa, diabetic retinopathy)
for which light therapy should be
used only in conjunction with ophthalmological
monitoring. Certain medications
may increase the eye's sensitivity
to light, and patients using them
should also be followed by an ophthalmologist. |
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| Q: |
How
did this treatment develop? How
long has it been in use? |
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| A: |
The first demonstration of clinical
effect was in the early 1980's.
Soon after, several research centers
initiated clinical trials, and more
than 2,500 SAD patients have been
studied to date. The method has
also been used in private practices,
in most cases by psychiatrists,
but also by family doctors, psychologists,
and psychiatric social workers and
nurses. The number of clinicians
offering light therapy is increasing
dramatically year by year, though
compared to drug treatments or psychotherapy,
the method is not yet in widespread
use. |
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| Q: |
Are
the lights medically approved? Is
a prescription needed? Does insurance
cover their cost? |
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| A: |
The American Psychiatric Association,
the U.S. Public Health Service Agency
for Health Care Policy and Research,
a Canadian Consensus Group of clinician-researchers,
and our Society have published clinical
guidelines and endorsed the use
of light treatment for winter depression.
The light apparatus is not a prescription
item, and its therapeutic use is
currently still under consideration
by the Food and Drug Administration.
Pending FDA's decision in the matter,
its authority cannot be superseded
by guidelines that have been issued
by other agencies. Light boxes are
commercially available, but anyone
suffering serious depression should
seek a doctor's recommendation before
obtaining a unit, and use it under
the doctor's supervision. Some people
have been successful in obtaining
insurance reimbursement for purchase
of light therapy apparatus, based
on their physician's statement that
the lights are medically indicated
and effective for the individuals.
Medicaid does not yet cover this
expense.
Our Society makes available to clinicians
a packet of information, including
a statement of our position on light
therapy for SAD, for use in supporting
insurance claims. If the insurance
policy covers psychiatric care or
psychotherapy, it is very likely
that it will reimburse for clinical
sessions involved in diagnosis of
SAD, evaluation for light treatment
and follow-up supervision. |
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| Q:
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How
much do the lights cost? Can individuals
build them for personal use? |
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Light therapy apparatus is available
from several manufacturers at prices
ranging from approximately US$200
to US$500, depending on how elaborate
the design features are. We do not
recommend home construction of the
apparatus. Output must be specifically
calibrated for the proper therapeutic
effect. A danger of creating electrical
or heat hazard also exists. The
apparatus on the market should have
been carefully evaluated for output
intensity, compatibility of components,
visual comfort, maximum transmittance
with minimal heat build-up and,
importantly, clinical efficacy in
controlled studies. These factors
should be checked before purchasing
any light system. Even though companies
are not permitted to make medical
claims for apparatus, some commercial
devices do meet the standards of
those that have been used in published
research. |
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| Q:
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Where
do I get a light box? |
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| A: |
Our Society does not specifically
recommend any particular lighting
product for clinical, research or
general purpose use. Furthermore,
it maintains no responsibility for
implicit or explicit claims for
efficacy or instructions for use
that may be contained in literature
written and distributed by manufacturers
and suppliers of apparatus. We urge
patients to seek the advice of an
experienced clinician regarding
the use of bright light for treatment
purposes. |
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| Q:
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Is
free treatment available? |
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Free treatment is available for
research volunteers at SAD clinical
research centers in the United States,
Canada, Europe, Japan, Australia
and elsewhere. Recruitment for the
winter season often begins in late
summer or early fall. |
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| Q:
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Can
I treat my SAD symptoms on my own?
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| A: |
Like other forms of depression,
SAD can seriously disrupt a person's
functioning and quality of life.
We therefore do not recommend that
people with SAD treat themselves
without the supervision of a qualified
professional. Light therapy needs
to be monitored in order to achieve
the best possible clinical outcome
and fewest possible side-effects.
For some people, other therapies
may be required in conjunction with
lights. For these reasons, a knowledgeable
professional is an invaluable resource
in treating SAD. |
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What
other treatments are available for
SAD? |
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Apart from moving to or taking long
vacations in a climate with more
available natural light, some sufferers
find that standard antidepressant
medications provide a measure of
relief, even if they do not reach
their normal level of well-being
until spring or summer. Although
light therapy is often fully adequate
for treating SAD, patients have
been helped by other means as well,
including psychotherapy, stress
management, and exercise. |
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| Q:
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Is
light treatment useful for conditions
other than SAD? |
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| A: |
Certain seasonal problems focused
on winter can occur without depressed
mood, such as increased appetite
with overeating and weight gain,
oversleeping, daytime fatigue, and
worsening of premenstrual symptoms.
(Of course, these problems are often
also associated with SAD). Light
therapy has been used successfully
in such cases, although additional
research is still needed. Applications
for certain nonseasonal problems
also appear promising. One is for
treatment of delayed sleep phase
disorder, in which a person cannot
fall asleep till very late nor awaken
at any early-morning hour. The method
may also be useful to assist with
jet-lag adjustments, when a person's
internal clock gets out of sync
with local time because of rapid
crossing over time zones. Shift
workers may also benefit by appropriately
timed bright light exposure to ease
the adjustment to rotations as well
as to counteract difficulties on
the night shift. Light therapy may
also be useful for nonseasonal depression,
bulimia nervosa, and premenstrual
syndrome. |
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Note
that the information on these pages
do not substitute for medical consultation.
SLTBR is unable to answer clinical
questions, and recommends that you
contact your family physician or
the nearest university medical center
for the name of a mood disorders
or sleep disorders specialist. |
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Copyright
SLTBR, 1994, Revised May, 2000.
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