SAD Frequently asked questions

Are women at higher risk than men?

There is no question that more women than men have come in to report winter depression symptoms and have sought counseling and treatment. And more women than men have participated in research studies. I think it's somewhat more likely that a woman will suffer from SAD, but that's not to minimize the impact on men. It's terribly important to teach men that this can hit them just as severely and not to brush it away.

What causes SAD?

Our nervous system relies on a daily exposure to early morning light for the internal biological clock to stay synchronized with the external world. In the fall, the sun is rising later and later in the morning. So when we allow our internal clock to drift later as sunrise drifts later and the days grow shorter, that's when we see the onset of both the physical and the emotional symptoms.

How do you differentiate between SAD and normal depression?

One mistake that doctors often make when a patient comes in with a depression is that they fail to note the time of year, and they fail to ask what the mood was like at the opposite time of year. So a person comes in in November and is feeling lousy. The first question to ask is: How were you feeling in June and July? Next question to ask is: How were you feeling at this time last year and the year before?

You can begin to refine your thinking about that even before you see a doctor by using an automated questionnaire available to everyone on the Web at www.cet.org. It's called the Personalized Inventory for Depression and SAD, and it asks you symptom by symptom what you have and when you have it, and how severe it is. On the basis of that, an algorithm can very confidently say, 'This looks like SAD or this does not look like SAD.' The smart thing to do is to get the results from that questionnaire and present them to your doctor.

Is diagnosis often delayed?

The lucky thing about SAD for SAD sufferers, if there is a lucky thing about it, is that they know it's going to pass, whereas in other depressions you can't be sure. There are even depressions that last for years. So the SAD sufferer has that firm knowledge that, 'Come the second week of May, I'm going to be back to myself.'

For that reason, many patients with SAD have resisted coming in for clinical care, because they say, 'I'll bear it out, and I know I'll be better.' And it's a mistake, because their lives can be severely compromised for five to six months of the year unnecessarily.

How are the holiday blues tied to SAD?

It's not difficult to confuse holiday depression with SAD because of the timing. While some people with SAD begin to feel badly as early as September and October, a large number really don't feel the major slump until after Thanksgiving and towards Christmastime. They'll know, however, that there isn't some emotional connection with the holidays that's triggering their depression if it doesn't let up until April or May, because a holiday depression will pass shortly after New Year's. January and February are the worst months of the year for SAD symptoms.

How is SAD treated?

Winter depression has responded well to a number of different interventions. The primary therapy is bright light therapy in the morning after you wake up. Another light therapy option includes dawn simulation therapy, in which you force an artificial sunrise in your bedroom while it's still dark outside.

Another option is negative air ionization therapy, where you create summer-like conditions in the circulating air environment, either while you sleep or during the day. Negative air ions are very high in the environment in highly humidified environments, but indoors, especially in the winter with the heater on, there's a paucity of negative air ions, and that acts badly on mood.

Another option is standard antidepressant medication, which you really need to use only during the difficult months of the year. What we realize now is that the whole gamut of depression, whether seasonal or not, is modulated by the level of serotonin activity in the brain, and that's why the selective serotonin reuptake inhibiting (SSRI) drugs, such as Prozac or Zoloft or Celexa, are useful as during depression. They activate the serotonin system, and mood lifts. The studies that have been completed so far for SSRI drugs for SAD do show some improvement, but with not the extreme and rapid alleviation of symptoms that we see with light therapy.

And finally, there are indications that cognitive behavioral therapy can be effective in helping people deal with the challenges of winter and lifting their mood and improving their function.

How does bright light therapy work?

When we use bright light therapy, we're introducing a level of light indoors that does not come from any normal home lighting appliance. It's a level equal to outdoor light about 40 minutes after the sun rises.

The light box is set up on a desk or kitchen table such that the angle of light exposure comes down at your eyes. Its action is on the eyes, not the skin, and there are light receptors in the eyes that are specialized for sending signals to the biological clock. When we stimulate those receptors with light at the appropriate time of day for the individual, it resets the clock to its springtime mode, and that's when we begin to see the alleviation of symptoms. The average treatment duration is 30 minutes a day.

What time of day should someone receive bright light therapy?

The optimum time for taking light therapy in the morning is best gauged by determining the onset of melatonin in the evening. In external clock time, this can differ by several hours between individuals, and using the light too early or too late will greatly reduce its benefit.

Melatonin is a nighttime hormone. At a certain point in the evening, levels of melatonin begin to rise because the biological clock has told the pineal gland in the brain that produces melatonin, 'Now it's night.' In winter, the nights are longer, and so our biological clock is prone to turn off melatonin production later in the morning..

Are there side effects of light therapy?

It's critical when you use light therapy to use well-designed apparatus that completely screens out ultraviolet (UV) rays. The long-term cumulative exposure to UV rays is bad for the skin, and for the cornea and lens of the eyes. Unfortunately, there is a wide array of apparatus available for sale on the Internet, which has never been medically evaluated, and the Food and Drug Administration has no regulatory policy for this technology. But the Web site of the nonprofit Center for Environmental Therapeutics lists six criteria for choosing a light box.

Should people with symptoms that are not alleviated by therapy move?

Many people who have suffered this terribly at Northern locations, like New England or Minnesota, will ask me, 'Should I make a major life change and move down to Atlanta or Miami or Dallas?' And the answer is, it's worth a try, but don't make the commitment to move until you have taken an extended vacation at that location in winter, because the amount of latitude change that any individual needs to eliminate this problem varies.