Full text of DOI:10.1089/107628001300000651

Update on Seasonal
Affective Disorder
Light Therapy and Herbs Relieve Many Symptoms
Hyla Cass, M.D.
Seasonal and Diurnal Cycles
The relationship between light and
behavior is not limited to human beings.
easonal affective disorder, or SAD,
affects approximately 5 percent of
U.S. adults, or approximately 10
Many animals show profound behavioral
changes in late fall and winter—birds
migrate, bears hibernate, and salmon
return to their birthplaces. In fact, aside
from the emotional symptoms, SAD suf-
ferers seem to be in a kind of hibernation
mode during the cold, dark months. Once
the longer days of spring arrive, these
people wake up, and become reenergized.
This may be a normal variation of a bio-
logic response. Individuals who are prone
to SAD are more sensitive to seasonal
light deprivation, which triggers bio-
S
million Americans. As with most forms of
depression, the problem tends to run in
families and afflicts four times as many
women as men. Also, the higher the lati-
tudes’ distance from the equator north or
south, the greater the risk for developing
SAD. For example, studies show that
approximately 1 percent of Floridians suf-
fer from SAD in contrast to 10 percent of
Alaskans. Climate is also a factor, with
colder weather related to a higher SAD
2
chemical changes in the brain.
1
incidence. In addition, an estimated
On closer examination, we see that our
internal biologic clocks are synchronized
to the 24-hour “diurnal” light–dark cycle.
This allows us to be alert by daylight and
become drowsy as the sun sets. This pat-
tern worked well for Stone Age people,
who could rest and regenerate during the
dark night hours. This pattern continued
through most of human history. Howev-
er, the invention of the light bulb has
enabled us to run counter to our inborn
cycles. No longer living a primal life, we
are called upon to function during hours
of darkness. Can you imagine the slow-
down that would occur if everyone
turned in at 5 PM in the late fall and win-
ter and slept until the sun came up?
1
3–25 percent of the population experi-
Hyla Cass, M.D., Pacific Palisades, California.
ences a less-serious version of SAD com-
monly known as “the winter blues.”
SAD can affect children as well as
adults. This is particularly important to
recognize. Otherwise these children may
have the added burden of being labeled
as “difficult” or “lazy” by parents and
teachers.
when the light- or photoperiods are long,
melatonin secretion is at its lowest. As
winter approaches, the period of daily
darkness lengthens, and more melatonin
is released into the blood.
SAD Symptoms
Light Therapy
Most people who experience SAD will
become melancholy to the point of experi-
encing real grief at times despite the
absence of a specific, acute interperson-
al/environmental cause. Other people
become more anxious or irritable than
usual, some to the extent of committing
violence. Other symptoms may include
fatigue, difficulty in concentrating, social
withdrawal, increased sensitivity to rejec-
tion, reduced activity, reduced libido,
increased appetite, especially for carbohy-
drates, and weight gain.
The October 1998 issue of Archives of
General Psychiatry includes reports of
placebo-controlled trials of bright light
treatment, now an accepted treatment
4
for SAD. To suppress melatonin, this
The Melatonin Connection
therapy exposes the individual to a set
of full-spectrum fluorescent lights at a
level of 2500–10,000 lux for 30–120 min-
utes during the early morning hours.
(One lux is the brightness of a candle at
a distance of 1 meter.) The 10,000-lux
light level is the most efficient, usually
The diurnal sleep/wakefulness cycle
appears to be regulated by the sleep neu-
rohormone melatonin. It is secreted by
the pineal gland in response to darkness
and is suppressed by the presence of
3
light. Thus, during spring and summer,
5

6
ALTERNATIVE & COMPLEMENTARY THERAPIES—FEBRUARY 2001
Light may produce
antidepressant benefits within 1 week.
on the light box is a portable light visor
that directs light into the eyes. Yet
one third of women with PMS also
have SAD, with increased weight gain
and need for sleep in winter.
Resources on Seasonal
Affective Disorder
another light option is a simulated-
dawn device using a nightstand light
fitted with a timer and dimmer. It slow-
ly brightens over 2 or 3 hours until the
person awakens. In one study, 6 of 8
sufferers with SAD experienced sub-
stantial relief after 2 weeks of awaken-
i n g t o s i m u l a t e d s u n r i s e s . T h e
lightbulbs in all of these devices are
full-spectrum minus the ultraviolet,
because the latter can cause sunburn
and increase the risk of developing skin
cancer. SAD symptoms typically begin
to abate approximately 1 week after the
start of phototherapy, with the full
effect taking an average of 2–3 weeks.
Symptoms recur, however, if treatment
is discontinued.
• Shift work—Night-shift workers are
also more susceptible to winter blues.
They need to be exposed to sufficient
light, whether natural or artificial, to
keep their melatonin levels in check.
Bright light can also improve sleep
and alertness in night-shift workers.
Furthermore, night workers benefit
from protecting themselves from expo-
sure to conflicting cues from sunlight
by wearing dark goggles on their way
home from work, by sleeping at con-
sistent times, and by light-proofing
Organizations
American Academy of Family
Physicians
1
1400 Tomahawk Creek Parkway
Leawood, KS 66211-2672
Web site: familydoctor.org/hand
outs/267.html
Depression and Related Affective
Disorders Association (DRADA)
Affiliated with the Department of Psychiatry
Johns Hopkins University School of
Medicine
Meyer 3-181
00 North Wolfe Street
7
their bedrooms.
6
• Bulimia nervosa—A study published in
1998 reported that approximately one
third of people with this disorder have
SAD and binge and purge more in win-
ter. Light therapy acutely and rapidly
improves both their moods and disor-
Baltimore, Maryland 21287-7381
Web site www.med.jhu.edu/drada/
Tools For Wellness
Investigators have identified several
other conditions and situations that may
be associated with SAD and that respond
to bright light treatment as well. These
include:
9
755 Independence Avenue
Chatsworth, CA 91311-4318
800) 456-9887
(
8
,9
dered eating behaviors.
Web site: www.toolsforwellness.com
National Organization for Seasonal
Affective Disorders (NOSAD)
P.O. Box 40190
Washington, DC 20016
NOSAD is a support group to help SAD
•
Nonseasonal depression—Light may pro-
duce antidepressant benefits within 1
week, in contrast to psychopharmaco-
logic treatments, which typically take
several weeks. A recent review of clin-
ical trials found that bright light thera-
py for nonseasonal major depression
produced statistically significant
reductions in mood symptoms of
approximately 12–35 percent on the
Hamilton Depression Rating Scale.
These results are comparable to those
obtained with antidepressant medica-
St. John’s Wort and SAD
Just as light therapy has been shown to
be as good as antidepressants for SAD,
other research shows that St. John’s wort
(Hypericum perforatum) can be just as effec-
tive, without the side-effects of the medica-
sufferers and their families.
Web sites
Life Extension Foundation
www.lef.org/protocols/abstracts/abstr
1
0
tions. One study evaluated the effects of
900 mg of St. John’s wort extract (standard-
ized at 0.3 percent hypericin) daily and
varying levels of light therapy on 20 SAD
patients with significant levels of depres-
sion. In 4 weeks, the group that received
brighter light (3000 lux for 2 hours each
day) showed a 72-percent drop in depres-
sion scores, while the group treated with
dim light (less than 300 lux) had a drop of
only 60 percent. Researchers concluded
that St. John’s wort is almost as effective as
light therapy and is more convenient.
-
098.html
Seasonal Affective Disorder, Depres-
sion or Winter Blues Home Page
www.go2net.org/nosads/home.html
WebMD
5
tions.
onhealth.webmd.com/conditions/resourc
e/conditions/item,486.asp
•
Premenstrual syndrome—A 1997 study
found that patients with premenstrual
syndrome (PMS) symptoms often
show substantial seasonal patterns,
with worsening of mood and PMS
requiring just 30 minutes daily from
October to April. Afternoon or evening
sessions are not as effective. A variation
6
symptoms in winter. Approximately

ALTERNATIVE & COMPLEMENTARY THERAPIES—FEBRUARY 2001
7
Study participants with SAD
responded equally well to exercise and light.
1
1
12
5. Kripke, D.F. Light treatment for nonseasonal
depression: Speed, efficacy, and combined
treatment. J Affective Disord 49:109–117, 1998.
In a more recent study, members of
the SAD Association took part in a mail-in
survey, before and after 8 weeks’ treat-
ment with St. John’s wort (Kira [Lichtwer
Pharma, U.S., Inc., Eatontown, New Jer-
sey]) and with one group also adding light
therapy daily. The mean score on the
Hamilton Depression Rating Scale of 168
patients using Kira alone was 21.3. This
fell to 13 at the end of the study (P< 0.001).
The corresponding figures for 133 patients
using Kira + light therapy were 20.6 and
sion. The researchers found that oxygen
consumption was similar, before treatment,
in the nondepressed subjects (n = 18) and
depressed nonseasonals (n = 18), but was
comparatively lower in subjects who were
affected by SAD. One week of physical exer-
cise (pedaling daily on a bicycle ergometer
for one hour) increased the oxygen con-
sumption in the SAD group and lowered
oxygen consumption in the depressed and
nondepressed nonseasonal groups. One
week of 2 hours per day of bright light treat-
ment raised oxygen consumption in nine
subjects with winter depression and nine
nondepressed subjects but had no signifi-
cant effect on oxygen consumption in nine
study participants with nonseasonal depres-
sion. Study participants with SAD respond-
ed equally well to exercise and light,
whereas patients with nonseasonal depres-
sion showed a significantly better therapeu-
tic response to exercise.
6
. Lam, R.W., et al. A controlled study of light
therapy for bulimia nervosa. Am J Psychiatr
1
51:744–750, 1994.
7
. Martin, S.K., Eastman, C.I. Medium-intensity
light produces circadian rhythm adaptation to
simulated night-shift work. Sleep 21(2):154–165,
1998.
8
. Lamberg, L. Medical news and perspectives:
Dawn’s early light to twilight’s last gleaming. . . .
JAMA 280(18):1556–1558, 1998.
9
. Braun, D.L., Sunday, S.R., Fornari, V.M.,
1
1.8, respectively (P< 0.001). Members of
Halmi, K.A. Bright light therapy decreases
winter binge frequency in women with bulimia
nervosa: A double-blind, placebo-controlled
study. Compr Psych 40(6):442–448, 1999.
10. Martinez, B., et al. Hypericum in the treat-
ment of seasonal affective disorders. J Geriatr
Psychiatry Neurol 7(suppl. 1):29–33, 1994.
both groups experienced significant
improvement in reducing anxiety, loss of
libido, and insomnia. There were no sig-
nificant between-group differences on any
measure except that improvement in sleep
was greater in the St. John’s wort + light
group (P< 0.01). Based on this survey, St.
John’s wort would appear to be almost as
effective as light in treating SAD.
My own clinical experience has been
similar. Many people with less-severe
forms of SAD do quite well on the herb,
without the need for the lights. The addi-
tion of B vitamins is also important, partic-
11. Wheatley, D. Hypericum in seasonal affec-
tive disorder (SAD). Curr Med Res Opin
1
5(1):33–37, 1999.
1
2. Pinchasov, B.B. et al. Mood and energy reg-
As the dark skies of winter settle upon
us, SAD days are coming to those who are
so affected. It behooves us to be prepared
ulation in seasonal and non-seasonal depres-
sion before and after midday treatment with
physical exercise or bright light. Psychiatry Res
94(1):29–42, 2000.
to help them find the right treatment.
n
ularly vitamin B , because these vitamins
6
act as cofactors in maintaining adequate
levels of neurotransmitters, especially
serotonin. In addition, L-tryptophan,
References
Hyla Cass, M.D., is an integrative psychiatrist
in Pacific Palisades, California. She is also an
assistant clinical professor of psychiatry at the
University of California, Los Angeles, School
of Medicine. She can be reached at hyla@cass
md.com She is the author of St. John’s Wort:
Mother Nature’s Blues Busters (New York:
Avery-Penguin-Putnam, 1998) and Kava:
Nature’s Answer to Stress, Anxiety, and Insomnia
(with Terrance McNally; Rocklin, CA: Prima
Health, 1999).
1
. Mersch, P.P., Middendorp, H.M., Bouhuys,
A.L., Beersma, D.G., van den Hoofdakker R.H.
Seasonal affective disorder and latitude: A review
of the literature. J Affect Disord 53(1):35–48, 1999.
2. Guillemette, J., Hebert, M., Paquet, J., Dumont,
M. Natural bright light exposure in the summer
and winter in subjects with and without com-
plaints of seasonal mood variations. Biol Psych
4(7):622–628, 1998.
. Lewy, A.J., Wehr, T.A., Goodwin, F.K., New-
some, D.A., Markey, S.P. Light suppresses mela-
tonin secretion in humans. Science 210:1267–1269,
5
00–2000 mg per day (administered via
prescription from a compounding phar-
macy), or 5-hydroxytrytophan (50–150 mg
per day) can increase serotonin levels.
Aerobic Exercise and SAD
4
3
Adequate aerobic exercise, especially out-
doors, is also helpful. A recent study com-
pared the effects of physical exercise and
bright light on mood, body weight, and oxy-
gen consumption in age-matched groups of
women with winter depression (SAD), with
nonseasonal depression or without depres-
1
4
980.
To order reprints of this article, write to or call:
Karen Ballen, ALTERNATIVE & COMPLE-
MENTARY THERAPIES, Mary Ann Liebert,
Inc., 2 Madison Avenue, Larchmont, NY 10538-
1962, (914) 834-3100.
. Eastman, C.I., Young, M.A., Fogg, L., Liu, L.L.,
Meaden, P.M. Bright light treatment of winter
depression: A placebo-controlled trial. Arch Gen
Psych 55:883–889, 1998.