The extra booze-swilling hour this past weekend may have been swell, but that tiny extension marked the beginning of dwindling daylight hours. Now, when you’re stepping out of a late-afternoon class into darkness instead of dusky light, “falling back” doesn’t seem so appealing.

Gloomy days can cast a depressing pall over everyone’s winter life, but for some seasonal depression is a cruel clinical reality. In Wisconsin, 17 percent of the population suffers from Seasonal Affective Disorder, an extreme form of the winter blues, while an additional 8 percent experience a less severe form of SAD, University of Wisconsin associate psychiatry professor Nancy Barklage said.

UW Counseling and Consultation Services director Robert McGrath said differentiating the disorder from lower-level bouts of sadness is a matter of degree.

“If you tend to be a little down in the winter, that’s one thing,” he said. “But if you actually get depressed — your body seems out of sync, your sleep patterns are messed up, your eating patterns are messed up — when it starts truly interfering with your daily life, that’s when I would call it SAD.”

Triggered by the lack of light that begins as soon as September and potentially lasts until early spring, SAD symptoms include lethargy, poor attention span, altered appetite, sleepiness, cravings for sugary or starchy foods and feelings of despair. While inhabitants of northern latitudes are more susceptible than those living in the south, experts say the disorder equally affects all other demographic groups.

“It feels like you’re sort of half asleep,” McGrath said. “You know you’re awake, but you’re not clicking on all cylinders. For the people who are most sensitive, it feels like nothing’s worthwhile.”

In the spring, however, despair turns to elation.

“Some people feel incredible relief and some tend to get in trouble,” McGrath said. “They just feel elated and sometimes make poor judgments. I know one person who realized he kept getting into unfortunate relationships every spring.”

Although theoretically everyone is equally susceptible to SAD, stressful or unhealthy conditions can exacerbate the condition.

“Students are vulnerable because of stress,” said Greta Guenther, a clinical nurse specialist in psychiatry at UHS. “They don’t get enough sleep, and they don’t eat right. They study hard and party hard.”

McGrath said students’ irregular sleep schedules decrease the already diminished amount of light per day.

“College students’ sleep patterns are a bit off already; when you go to bed at two or later and get up at 12 you get, at best, four and a half hours of light,” he said. “That makes college students pretty susceptible.”

SAD science

Like many mental-health illnesses, SAD’s scientific roots remain elusive. While it is obvious that lack of light is the major cause, experts are still debating exactly how increased darkness causes the disorder.

“It’s still not totally clear what the mechanism of action is,” UW clinical assistant psychiatry professor Jeffrey Anders said. “In terms of psychiatry, there’s a lot that isn’t known about the cause of the chemical basis of depression. For many psychiatric disorders, it isn’t totally clear. That’s more the norm.”

While uncertainties abound, three main theories have emerged from the discussion, Barklage said. Each involves the production of neurotransmitters, substances manufactured in the brain that she said,”help brain cells communicate.”

Two implicated neurotransmitters are melatonin and serotonin, both produced in the brain’s pineal gland. Production of melatonin, which has been linked to sleep, increases with darkness and is suppressed by light. Conversely, levels of serotonin, a stimulant, increase with light and decrease in the dark. Serotonin output levels have been associated with other forms of depression.

“One group believes melatonin is involved, other people believe it’s serotonin, and other people believe that it’s an unknown factor having to do with circadian rhythms,” Barklage said. “You hear a lot of people make a lot of claims about what they believe, but we really don’t know. We’re still trying to discover what makes it work.”

Furthermore, limiting causation to only melatonin and serotonin levels may oversimplify the process. Brain pathways, called circuits, are complicated and involve connections with different brain regions, UW Depression Treatment Program director Gregory Kolden said.

“Depression or SAD is not a simple neurotransmitter deficit,” he said. “It’s not as simple as there’s too much or too little.”

Stopping SAD

Fortunately for those who suffer during winter months, the medical uncertainty swirling around SAD does not extend to the treatment realm. Light therapy, usually involving bright-light boxes, can swiftly remedy the disorder. Sitting in front of a light box for a short period of time each day, typically 20 minutes to an hour, can drastically decrease depression.

“Light is typically placed within 18 inches of people’s eyes; they don’ t have to be looking at it, but they have to be facing it,” Anders said. “There’s a certain intensity needed to effectively treat SAD that’s thought to be in terms of lux — that’s light intensity — between 2,500 and 10,000 lux. Your standard room at night with a few lights on is in the several-hundred lux range. On a really bright, sunny day it’s about 100,000 lux, 10 times the amount needed.”

UHS offers light boxes for free, two-week trial periods, McGrath said.

“You’ll know in three to four days whether you’ll respond or not,” he said. “A person with SAD will start feeling better pretty quickly.”

Offering trial light boxes since 1995, UHS has developed regular policies and protocols for administering light therapy to students, Guenther said. She said even those suffering from mild winter blues can benefit from light therapy.

“A student doesn’t have to have full-blown depression, like they can’t do school,” Guenther said. “They can have winter blues and still benefit from light therapy. It’s not scary.”

Alternatives to light therapy include anti-depressant drug treatment and more traditional health initiatives like eating right and exercising often.

“All the basics that are really boring that people don’t want to hear about really do help,” Guenther said.

Although home-based and UHS treatment is free for UW students, it can be difficult to persuade insurance firms to pay for further therapy.

“Insurance companies seem reluctant; they really want [SAD] well-documented, and they want to know it’s recurrent,” McGrath said. “By the time someone gets it documented, sometimes it’s two years, three years out.”

Due to comparatively high initial light-box costs, insurance companies may be more willing to spring for drug therapy.

“In terms of light therapy it’s hard — only a few insurance companies will reimburse for a photo therapy light,” Anders said. “They feel it’s not a validated treatment — it’s expensive compared to medication. In the short term, if someone doesn’t respond, the company hasn’t spent $300 down.”

Mythical remedy

Superficially like extra-large light boxes, tanning beds are popularly thought to help fight SAD or winter blues. Most experts, however, refute that assumption. Although tanning may temporarily combat depression, it has little overall effect.

“Tanning would be warm and bright — it would be a reasonable coping mechanism, but it’s not an effective form of light therapy,” Anders said.

Furthermore, concerns that UV radiation causes skin cancer has led many healthcare experts to warn against tanning.

“We don’t recommend tanning booths for a couple of reasons,” Barklage said. “Number one, they don’t work. Number two, they are dangerous. Tanning booths do cause skin cancer.”

Additionally, the overwhelming majority of studies have shown light must enter the eyes through the retinas to effectively resist SAD. Heavy tanning goggles block this effect.

“In early studies they wrapped people up like mummies and only exposed their eyes to light and then they had other people who took all their clothes off and closed their eyes,” Barklage said. “The people that got better had the light hit the retina.”

One study found applying light to the back of the knee had positive results, but the researchers did not know why it worked and have not been able to duplicate the results, Barklage said.

While traditional light therapy is proven to be extremely useful in treating SAD patients, Kolden emphasized the importance of full depression analysis.

“Other life stresses are also important in terms of comprehensively treating this kind of depression,” he said. It’s not always related to other stresses, but many times they go hand-in-hand. It’s not just a simple, ‘I’m not getting enough light, and then if I get enough light everything will be wonderful.'”