Essay/Term paper: How moods are affected by the sun

Essay, term paper, research paper:  Science Reports

How Moods Are Affected By The Sun


Jared Sousa
1/20/96
Descriptive Research

Thesis: The amount of sun people receive affects their mood.

A young woman lies asleep on a cold, overcast winter morning. At 4 A.M., a
faint incandescence radiates from a light bulb placed near her bed. The light
gradually gains intensity and covers until 6 A.M., when the woman awakes. She
had just experienced a simulated dawn of a new day. After being treated with
this for several days, the woman's annual winter depression slowly goes away.
Does this mean that the less sun you get the worse you feel, or perhaps the
more you get the better your mood? It is very possible that you may feel this
way as millions of people worldwide have experienced it first-hand. This
phenomena is still sort of a mystery as many researchers don't completely
understand why this happens. "It may be that certain individuals have inherited
vulnerability that causes them to develop depression in the absence of exposure
to sufficient environmental light"1. Frederick A. Cook, the arctic explorer,
provided a vivid description of the effects of prolonged darkness on the human
psyche: "The curtain of blackness which has overfallen the outer world has also
descended upon the inner world of our souls," Cook wrote in his journal on May
16, 1898, "Around our tables . . . . men are sitting about sad and dejected
lost in dreams of melancholy. For brief moments some try to break the spell by
jokes, told perhaps for the 50th time. Others grind out a cheerful philosophy;
but all efforts to infuse bright hopes fail."2 Some believe that light affects
the body's ability to make serotonin, a neurotransmitter that helps induce
feelings of calm and well being. The eye's sensitivity may also play a part in
sun/mood relations. A study was done to a group of people in the winter and
summer. In the winter the many individuals experienced much more difficulty
seeing dim light after sitting in the dark for a while.3 Another study done in
Vancouver shows that electrical activity in the retinas when a bright light is
shone, is significantly less in winter4.

As much as 5% of Americans suffer from Seasonal Affective disorder, also known
as SAD5. SAD is an illness in which the sufferers feel depressed, feel
lethargic, and they overeat . There is no known cause for this widespread
illness. Many researchers of SAD are speculating on the idea that SAD patients
might have seasonal variations in their melatonin secretions. A study of
melatonin patterns in SAD sufferers was done to determine if melatonin was a
factor in the disorder. Since mostly women are affected by SAD, researchers
used healthy women as the control. The researchers who found that the
significant difference in winter and summer pacemaking that occurred in SAD
patients also saw similar patterns in the healthy women. Other studies show
that a SAD sufferer's eye usually does not take in as much sunlight in the
winter as a normal person, which may exaggerate the depression and other
symptoms.6 Most SAD patients treated with light therapy for a few weeks usually
lose the depression. SAD patients that tended to eat more than one portion of
sweet things (such as chocolate, cake, or ice cream) per day usually found
temporary relief from their illness.7 Swiss scientists believe that the sweet
foods seems to "trigger" the release of the same mood-altering substances that
light triggers.

Nevertheless, light -- or lack thereof -- can really get under our skin. For
instance, "Rapid changes in the day length greatly modify the daily cycle of
sleep and melatonin secretion," report researchers led by psychiatrist Thomas A.
Wehr of the National Institute of Mental Health, ". . . brain mechanisms that
detect and respond to seasonal changes in day length may have been conserved in
the course of human evolution."8 The findings with the sun's affect on humans
matched those already observed in rats. Many of us have not yet realized what
an important factor light is in our daily life. "Light is a complex stimulus
that has been inadequately specified, given the intense clinical experimentation
of the last five years."9 Research with these results easily prove that the
sun and light really do alter our mood, and have a great influence on our lives.