Effectiveness of alternative light in light therapy

Abstract: We attempted to measure the effectiveness of light therapy in treating the symptoms of
Seasonal Affective Disorder using two different kinds of light, both a full spectrum light and a
fluorescent light. They first filled out the questionnaire with no extra ordinary exposure to
light during the winter months, then with exposure to a full spectrum light, then also after
exposure to a bright fluorescent light. We then analyzed the data from the questionnaires to
determine if the same benefits can be experienced from exposure to either light.

Hypothesis: We predict that only the full spectrum light will offer the benefits to mood and
energy during the winter months that are associated with Seasonal Affective Disorder. This
Hypothesis was proven correct. The subjects, when exposed to full spectrum light, experienced
benefits to mood and energy, but when exposed to a fluorescent light actually experienced negative
effects.

Intro: In this lab, we hope to determine whether the benefits enjoyed by the use of a full
spectrum light to treat the symptoms of Seasonal Affective Disorder can also be experienced with
exposure to the light of a very bright fluorescent light. Phototherapy has been used with a great
deal of success in recent decades to treat symptoms of Seasonal Affective Disorder (Rosenthal
671). According to many psychologists, large portions of the population suffer from seasonal
shifts in mood and energy. Those changes are usually called subsyndromal SAD, meaning they are
not great enough to be diagnosed but are still affected by seasonal changes to a degree (Lam,
148). These subjects suffer from many of SADís most frequent symptoms. The symptoms of
Seasonal Affective Disorder are often characterized by extreme fatigue or lack of energy,
increased need for sleep, carbohydrate craving, increased appetite, and weight gain during the
winter months (UBC/VHHSC 1). Reported frequencies of these symptoms include 94% decreased
activity, 95% increase in sadness and 88% increased anxiety (Rosenthal 671). It is also believed
that those same subsyndromal subjects could enjoy the same benefits that Phototherapy offered,
just as they suffered many of the same symptoms of those who were actually diagnosed Seasonal
Affective (Lam 150). The Clinical and Chronobiological Effects of Light Therapy on Nonseasonal
Affective Disorders states that light therapy ěsignificantly improved clinical symptoms of
depressionî. We relied heavily on this concept, and when choosing our subjects to test the
effectiveness of Light Therapy, we did not pursue people who had been diagnosed Seasonal
Affective.
Theories as to why this phenomenon occurs are varied but some believe sufferers are either
lacking a hormone such as serotonin that light exposure helps release (Education 1), or their
biological clock gets thrown off in the winter and needs to get reset (UBC/VHHSC 2). The
biological clock theory is also known as Circadian Rhythms theory, and is also thought to be able
to be treated with light at critical times (Sack, 101). These theories support the idea that
light therapy can alleviate the symptoms mentioned above. If exposure to light can aid the brain
in its normal functioning, then it might be a valid treatment for the disorder.
This raises the question of what kind of light makes light therapy effective. If lack of sunlight
during the shorter winter day is what causes the SAD symptoms, then only a light that replicates
the sunís light (a full spectrum light) will ease the symptoms of those suffering. If however, it
is just the general need for light, not specific light, then any very bright, including a
fluorescent, light will work for sufferers. Some studies have attempted to demonstrate that
various different kinds of light are as effective as treating SAD symptoms (mentalhealth 3).
Other studies seem to claim that only true replications of the suns rays in the form of full
spectrum lights will significantly decrease symptoms (Holisticonline 1). Some studies state that
the benefits of exposure may be evident in as little as three to four days for exposure as short
as fifteen minutes a day (Proaxis 1).
We hope to prove that not only is light effective in treating many of the symptoms associated with
SAD, but that only full spectrum lights are affective for easing these symptoms.
We are taking into account what studies say we should conduct our exposure. We placed the box at
eye level on a desk or table, or vertically on the floor approximately 3 feet away from the
subject (Rosenthal 672). We also took precautions to minimize the placebo effect by testing both
the full spectrum light and the fluorescent light (Sack 101). We told subjects when we
administered the test that we were simply evaluating two lights popular in Phototherapy, to see
which was more effective.
In this lab we hoped to demonstrate that the advantageous effects to mood and energy levels
achieved by exposure to a full spectrum light cannot also be enjoyed with exposure to a bright
fluorescent light.
METHODS: In our student generated project the affects of Seasonal Affective Disorder, known as
S.A.D., was tested by subjecting student test subjects to a full spectrum light over a period of
time. Less natural sunlight is present during the winter months. It is for this reason that our
experiment was conducted during this time with a total of 10 volunteer test subjects per test.
The test period was over a span of nine days. In the first three days of the experiment the
volunteers were not subjected to any extraordinary light, instead they just filled out a survey
composed of questions in which the answers shall portray their current physical and emotional
feelings. (Included in packet) The next three days a florescent placebo light was in the vicinity
of the subjects for twenty minutes. The placebo light was a light made to look like a valid
scientific light, but in actuality have no affect what so ever on the student subjects. The same
survey will be given to the volunteers before the light treatment and after, sometime later. Then
for the last three days of the experiment the real full spectrum light was used and once again the
survey will be given before and after the test. The full spectrum light is a light in which its
light rays resemble the sunís rays. Energy from the rays is absorbed through the eyes. The
survey has questions that are answered on a numerical scale. This way the survey will be easily
analyzed and interpreted, also easily put into graphs. Furthermore, from these surveys and graphs
statistical information can be derived and analyzed. By using the same test subjects for each of
the three periods of testing statistical information should be sound. The effects of the light
will be present in three to four days. After around the third day of testing with the full
spectrum light, significant changes in mood should take place. This will be easily shown through
the succession of answers to surveys over that three day period. Over the course of nine days we
surveyed ten subjects at the same time everyday. For three days straight we surveyed each
individual to determine their stress levels, happiness, ability to concentrate, self-confidence
and their energy levels. During the first three days people were honest about their feelings. For
the next three of the nine days we exposed our subjects to the full spectrum light. This light is
recommended by doctors because of its ability to simulate direct sunlight beams. We had each
subject fill out a survey before exposure and after exposure. Subjects proved to feel much better
after they were exposed to the light. Their stress level was reduced and their happiness levels
were raised. They appeared to feel better about their self-image after sitting in front of this
light, which shows that this full spectrum light really serves its purpose. Our subjects were more
energized and ready to continue working after they participated for the next three days. For the
last of the nine days we exposed our ten subjects to a fluorescent light to see if it would have
the same effect. This is exactly where our hypothesis comes in. We assumed that a bright light
would not have the same effects that the full spectrum does. This was proven in what we actually
found out about the fluorescent light. We found in our study that this light actually drained
energy and raises stress levels. We put our data into stat view and used paired t-tests to
evaluate the significance of the difference in both the energy and happiness levels after the two
kinds of light.

Student Survey
Please fill out this survey honestly
NAME_____________
DATE_____________

Rate on a scale from 1 to 10 to the best of your ability, 1 being the lowest and 10 being the
highest (CIRCLE ONE).
1.) Your energy level ( 1 2 3 4 5 6 7 8 9 10 )
2.) Anxiety or Stress level ( 1 2 3 4 5 6 7 8 9 10 )
3.) Happiness level (overall) ( 1 2 3 4 5 6 7 8 9 10 )
4.) Your self-image ( 1 2 3 4 5 6 7 8 9 10 )
5.) Ability to concentrate ( 1 2 3 4 5 6 7 8 9 10 )
Data Analysis

Using the Stat View program we calculated the data found beforehand in the results section. In
the first two entries we compared the results from the energy and stress questions for the period
shown for full light, no light, and the placebo light. For the entry where energy was compared we
found the results to show that energy went down after showing the placebo light and went up again
after exposing the subjects to the full spectrum light. During the placebo light testing, the
subjects loss energy probably due to the fact that they were sitting in front of a florescent
light that did not affect them like the full spectrum light. Then, obviously, the exposure to the
full spectrum light heightened the subjectsí energy as it was designed to. The second data entry
showed that on a whole stress went down after showing the subjects the placebo light, but then
went up after showing the full. This implies that the full spectrum light did nothing to decrease
stress in the subjects. Although these findings differ from the rest of our results, we believe
that they are external reasons, which we will extrapolate upon later. Data entry number three
shows that in the three days that we exposed the subjects to the full spectrum light stress
decreased and exposure to the placebo light made stress levels rise. In our fourth data entry we
compared the subjectsí energy levels. We discovered that both the placebo light and the full
spectrum light decreased energy levels in the test subjects. Data entry number five concluded
that both the placebo and the full spectrum light reduced happiness in the test subjects. The
sixth data entry showed concentration levels went down after exposure to the placebo light. The
data for the full spectrum light concluded there was no change in the level of concentration in
the subjects after exposure to the full spectrum light.
Throughout the results, there seems to be inconsistencies. For example, the second entry found
there to be an increase in stress after showing the full spectrum light to the subjects. In
contrast to that, data entry three showed the stress levels to decrease after the full spectrum
light was shown. The explanation of this is the first entry showed results from the whole time
period of the experiment (nine days), and the third entry presented the change in stress levels
form the first day the full spectrum light was shown to the last day it was shown. We have
attributed these differences in stress levels to the time the experiment was preformed; during the
two weeks before final exams. Many of our subjects were architecture students and many
architecture projects were due during our experiment. Our entries on energy levels also had
differing results. The first entry shows that on a whole, the test subjectsí energy went up.
However, our forth entry found the full spectrum to drain the subjects of their energy. Again, we
credited these differences to the timing of the testing.
Suggestions for Doing this Project Again
If one was to replicate this experiment, we have a few suggestions. One would be to expose the
subjects to the lights for a longer time period. We attained fair results using three-day periods,
but longer exposure time could bring better and more solid results. Another proposal for re-doing
this project would be changing the exposure to a time when the subject would not be under extreme
stress and deadlines. Another suggestion would be to lengthen the actual exposure time. We placed
the subjects under the lights for a twenty-minute time period. A longer time could possibly
produce more concrete results.

Looking Beyond the Project
This project brought up some other questions that would include further research. Some of these
were the following:
Would the full spectrum light be more effective if shown in the morning?
Why did the fluorescent light have negative effects on stress and energy?
What other factors does the full spectrum light effect?
Why do so many people display symptoms of Seasonal Affective Disorder?
Conclusion
With this experiment, we proved our hypothesis correct, in that only full spectrum lights gave
benefits to the symptoms of S.A.D. In fact, fluorescent lights had a negative impact on energy and
mood.

References
ěHolistic alternatives to medicine.î http://www.holistic.com/w_altermative.html.
[9 October 1999].

Iris Times, Educational Newsletter. ěNewsletter about sever mental illness.î
http://www.proaxis.com/~irisproject . [28 September 1999]

ěMental Health.î http://www.mentalhealth.com/book/p40-sad.html . [28
September 1999.

UBC/VHHSC Mood Disorders Clinic. ěInfo about Seasonal Affective Disorder.î
http://www.pschiatry.ubc.ca/mood/md_sad.html

Clinical and Chronobiological Effects of Light Therapy on Nonseasonalaffective

Disorders, Yamada, Naoto (15 June 1995)

Lam, Raymond W., M.D. Seasonal Affective Disorder and Beyond: Light
Treatment for SAD and Non-SAD Conditions. Washington D.C.:
American Psychiatric Press, Inc, 1998.

ěPhototherapy for Seasonal Affective Disorder.î Sack, David; Skewerer, Robert,
Et. Al. Journal of Biological Rhythms, Vol. 3, No. 2, 1988.

ěSAD: A Description of the Syndrome and Preliminary Findings with Light Therapy.î
Rosenthal, Norman; Gillin, Christian ET. Al. Archives of
General Psychiatry, Vol. 41, Jan. 1984.

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