Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=198602
Story Retrieval Date: 6/19/2013 10:17:52 AM CST
Courtesy Center for Environmental Therapeutics (http://www.cet.org)
This type of soft-white fluorescent lamp can be used right after waking in the morning.
Lighten your winter mood
Related LinksQ & A on bright light therapyMore information on seasonal affective disorder
Symptoms of SAD
• hopelessness or pessimism
• lack of interest in normal activities
• craving foods high in carbohydrates
• changes in weight
• difficulty concentrating
• difficulty remembering details and making decisions
• social withdrawal
Sources: National Institutes of Health and Mayo Clinic
Kristina DeLong started using the “happy light” two years ago to counteract symptoms of seasonal affective disorder, more commonly known as winter depression.
“I’m just a person who gets down when there’s not a lot of sunlight,” said DeLong, the owner of a pet boarding and grooming facility in central Illinois. She begins using light therapy when the clocks change in the fall and stops when sunshine is more rampant.
After researching on the Internet, DeLong bought her full-spectrum light online.
Although seasonal affective disorder, or SAD, is not a clinical condition like attention deficit disorder, it is a diagnostic subtype of depression.
“People who have a lot of episodes of depression are more liable to have seasonal affects in their mood,” said Dr. John Gottlieb, a psychiatrist at Northwestern Memorial Hospital.
Short winter days can cause the body’s natural clock or circadian rhythm to be out of sync with the sleep-wake cycle. People’s internal chronograph resets itself after sunrise even if they wake up before dawn. Incongruity between the two events could cause psychological problems, according to the “phase shift hypothesis.”
Seasonal affective disorder is “kind of like having jet lag but for five months,” said Dr. Alfred Lewy, an Oregon psychiatrist who treats patients with circadian rhythm disorders.
Those more susceptible to the winter doldrums include people who have bipolar disorder, a family history of depression or a parent with this seasonal pattern. Women are more prone to it than men, Gottlieb said. But because the problem exists on a wide spectrum, data collection about those affected by the condition doesn't exist, he said.
For most individuals, the light intensity of ordinary indoor lamps and ceiling fixtures fall well below the requisite amount needed for light therapy, which reorganizes the daily fluctuation of the hormone melatonin.
“On average, melatonin begins to be secreted between 8 and 10 p.m.,” Gottlieb said. As the levels increase, most people begin to nod off into sleep.
In winter, “when melatonin secretion shifts later in relation to the sleep cycle, this kind of misalignment contributes to circadian disruption and depression,” he said.
Light therapy is often more effective than antidepressant medication, he said. “In critical practice, most people respond to it in anywhere from three to seven days,” he said.
Those interested in light therapy can buy a system online that uses fluorescent bulbs and has a diffusing screen. Wattage should not exceed 10,000, Lewy said.
The lamp should be used soon after a person rouses out of slumber. Initially, one to two hours is recommended but once the body begins to respond, 20-30 minutes would suffice, Lewy said. Sit by the light box with your eyes open, but do not look directly into it. You may do regular activities like read or eat, he said.
Gottlieb said, “By administering light, you’re turning off melatonin at that time, and you’re causing it to appear earlier in the evening.”
A subgroup of patients doesn’t see any changes from using this regimen. These patients might do better with light exposure in the evening, Lewy said.
Side effects of the treatment include headaches, eyestrain or eye irritation, and nausea. Some patients become overactive — they have difficulty sleeping and become irritable or restless.
According to Gottlieb, seasonal affective disorder is “a clinically relevant degree of depression.” People should be evaluated and treated by a psychiatrist because “bright light is the equivalent of taking medication. It has equal potency.”
Yet “it’s not the right therapy for everyone,” he said. Medicinal alternatives include anti-depressants.
Sleeping later and going to bed earlier could also adjust a sleep-wake cycle to match circadian rhythm. This solution involves waking up a half hour after dawn to go outside and absorb some sunlight, assuming it’s not cloudy. Unfortunately, this treatment is only applicable to those who “have the luxury of adjusting [their] sleep time,” Lewy said.
Exercise and outdoor activity are “general recommendations for anyone who gets depressed, since they’re harmless and inexpensive,” he said. Yet, these have not been scientifically proven to help winter depression.
DeLong will not stop using her happy lamp anytime soon. “My battery went down, and I did notice a difference after not using it for a week,” she said. She felt more moody and tired: there wasn’t “as much spring in my step,” she said. She supplements light therapy with vitamin D and a lot of exercise.