About this time each year, Lisa Morris starts yearning for more light in her life.
The 31-year-old mother of two from Middle River suffers from seasonal affective disorder (SAD), a condition that prompts her to turn on a specially designed fluorescent lamp for up to an hour every morning when she rises.
Purchased from a medical supply outlet, the light helps ward off the ailment's most common symptoms: persistent fatigue, oversleeping and an increased appetite for sugary and starchy foods that often leads to weight gain.
"The light therapy does do the trick - but I still have my moments where I just want to go up and lay down in my room and not get up," Morris says.
The winter solstice occurred shortly after 1 a.m. today - the lowest point in a pattern of diminishing sunlight that begins each fall as the tilt of the earth's axis sends the northern hemisphere away from the sun. Today we get only 9 hours of sun.
Although SAD symptoms typically begin in September and October as the days get shorter, experts say the solstice period is when the effects of seasonal depression can be most pronounced, particularly if the condition is left untreated.
"It can really affect people for a major chunk of their lives, in a big way," said Dr. David Neubauer, a Johns Hopkins psychiatrist.
SAD is well-documented and affects up to 500,000 Americans - one reason scientists continue to work on improving treatments.
"A lot just depends on the amount of sunlight you're being exposed to," said Dr. Teodor Postolache, a psychiatrist who directs the mood and anxiety program at the University of Maryland School of Medicine.
Light therapy significantly improves symptoms for Morris - and for up to 75 percent of the patients who try it, Postolache said.
But Postolache is recruiting up to 100 volunteers for a three-year, $450,000 federal study to learn why light therapy doesn't work for everyone. Volunteers will get up to $200 to submit to blood tests, complete questionnaires about their moods, eating and sleeping habits - and then undergo six weeks of light therapy.
"We want to know what factors might be predictive of who responds to light treatment," he said.
Dr. Carol Watkins, a Baltimore County psychiatrist, periodically checks up on her seasonal depression patients to make sure they adhere to their light therapy or take antidepressants, if needed.
She also often tells patients to exercise when they use their light each morning, and she often uses the light herself before long-distance air travel to avoid jet lag. Most lights come with recommended exposure time and distances.
"For some people, it has the same effect as caffeine: It can keep you awake at night," said Watkins.
Experts believe the problem could date back to the first human migration to climates where daylight varies significantly with the seasons.
"I think people have always experienced it, but it's recognized now for what it is, and there's certainly a greater awareness these days that it exists," said Dr. Norman Rosenthal, a longtime researcher and a professor of clinical psychiatry at Georgetown Medical School.
Not surprisingly, this also is the season when sales of lamps designed for patients often peak.
"The shortness of daylight always drives sales," said Neal Owens, owner of Sunbox, a Gaithersburg store that sells six types of fluorescent lamps designed to combat seasonal depression.
Prices range from $180 to $400, and most of his worldwide customers are in northern climates, Owens said.
Owens said he started Sunbox in 1985 when seasonal affective disorder made it hard for him to do his job each winter as a Quaker State sales representative. He began looking to Rosenthal and other researchers.
Rosenthal, then at the National Institute of Mental Health, was just beginning studies examining why some people experienced depression that started in the fall and lasted through the winter each year.
Now he theorizes that seasonal depression is linked to levels of melatonin, a chemical secreted by the brain's pineal gland that is believed to be turned on by darkness and turned off by daylight. The hormone is associated with drowsiness.
For some reason, patients with SAD continue to produce melatonin after they wake up in the fall and winter, says Rosenthal, who has been publishing papers on its effects since 1984 and is the author of the book Winter Blues.
Rosenthal "really started the work in this whole field," said Dr. Scott Aaronson, a psychiatrist and director of research at Sheppard Pratt Health System in Towson.
Aaronson is working with Rosenthal to recruit up to 60 patients in a human clinical trial to see if Armodafinil, a medication approved in June for daytime sleepiness and narcolepsy, could be effective in treating SAD.
Volunteers will get the medication for five weeks to see how it compares with antidepressants now often prescribed for SAD. The antidepressants have side effects that include a reduced sex drive, Aaronson said.
"We're hopeful this will be a new approach to treatment," he said.
For information on joining the University of Maryland study, call 410-706-2324. For information on the Sheppard Pratt study, call 410-938-5050.