I wrote about Seasonal Affective Disorder (SAD) back in December 2009 and discussed exposure to full spectrum light as one of the effective treatments. A recent Canadian study suggests that this light therapy might also be effective for non-seasonal major depressive disorder (MDD). Previous studies on light therapy for MDD were poorly designed and inconclusive.
A study published this month in JAMA Psychiatry randomly divided 122 people from clinics in Vancouver and Toronto with moderate to severe non-seasonal depressive disorder into four groups: light therapy and fluoxetine hydrochloride (an antidepressant pill); light therapy and placebo pill; fluoxetine and placebo device (inactive ion generator); and both placebos. The light therapy consisted of a 30 minute exposure to a strong (10,000 lux) fluorescent light box every morning.
After 8 weeks improvement was observed in about 75% of the patients receiving the light therapy with the antidepressant; about 50% of those receiving the light therapy alone; about 29% for the antidepressant alone; and 33% for the placebos. The study concluded that “Light treatment, whether in monotherapy or in combination with fluoxetine, is efficacious and well tolerated in the treatment of nonseasonal MDD.” Surprisingly the antidepressant alone appears less effective than placebo, but this study was too small to draw any conclusions on this observation. An earlier study showed that fluoxetine and light had similar benefits in patients with SAD.
The researchers speculated that light therapy may resynchronize circadian rhythms that have become disturbed in MDD or rebalance neurotransmitter function. Sunlight triggers the pineal gland to produce more serotonin and less melatonin. Low serotonin is associated with depression and carbohydrate cravings; high melatonin with sleepiness and loss of concentration.
Michael Terman, PhD, professor of psychiatry, Columbia University, commented on the study:
“…the dramatic …result …[means that] 10,000 lux light therapy upon awakening or, by implication, a walk outdoors if the sun is up – now can be recommended to patients with recurrent depression, many of whom will respond without recourse to drugs.”So if you are suffering from depression, talk to your doctor about adding light therapy to your treatment. Caution – people with certain eye conditions or with bipolar disorder should not use the light therapy.
For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.