A new study reported in the May 2006 issue of The American Journal of Psychiatry, the official journal of the American Psychiatric Association (APA)compared
light therapy with the antidepressant fluoxetine (Prozac). The study, done
over three winters in Canada, concluded both are effective treatments for the
winter form of seasonal affective disorder (SAD).
Light therapy and antidepressants are each more effective than placebo,
but there have previously been few direct comparisons of them. This study was
double-blind. That is, all participants received light and a capsule each day.
One group
received low-intensity “placebo” light in addition to fluoxetine.
The other group received a placebo capsule and were exposed to 10,000-lux white
fluorescent light for 30 minutes a day.
The researchers discovered that light therapy showed two advantages over Prozac.
- Light therapy worked faster, having a
greater effect at one week.
- light therapy also produced less agitation and less sleep disturbance.
Though not mentioned in the study, another advantage of light therapy over
Prozac, as well as most antidepressants, is that light therapy has virtually no
side-effects. The most common side effects for Prozac include: dry mouth,
constipation, urinary retention, sedation, and weight gain. Other common side
effects are insomnia, restlessness, nausea, and tension headaches, lowered
libido and sometimes difficulty reaching orgasm. Fatigue and memory loss are
other possible problems.
Prozac is generally considered to have fewer side effects than most other
antidepressants.
Of course light therapy has very few side effects. However, headaches, eye
irritation, and slight nausea have sometimes been reported. These usually
disappear quickly.
In rare cases, hypomania (the manic phase of manic depression) can be
triggered by light therapy in patients with bipolar disease. This is also true of
Prozac.
Of course there is one last advantage of light therapy over Prozac: it is
much less expensive over time.
The report of the study of light therapy and Prozac are presented in the article, “The CAN-SAD Study: Randomized
Controlled Trial of the Effectiveness of Light Therapy and Fluoxetine in
Patients With Winter Seasonal Affective Disorder” by Raymond W. Lam, M.D., and
colleagues of the Mood Disorder Centre at Vancouver Coastal Health Research
Institute and the University of British Columbia. The rates of remission were 50
percent and 54 percent of enrolled patients for bright light and fluoxetine
(Prozac),
respectively.
You can read more about the study here.
