Half way through June, Mary realized that something was wrong. For a month she had been finding it increasingly difficult to get up in the mornings. Her energy levels were low and she was unable to concentrate. She had gained about three and a half kilograms and had difficulty avoiding high calorie snacks and desserts. She felt constantly tired and apathetic, and as the bills went unpaid and the household chores piled up, her feelings of guilt mounted. She felt disgusted with herself and very pessimistic about the future.
- lack of energy - increased sleep
- difficulty in awakening - weight gain
- decreased social activity - irritability
- carbohydrate craving - apathy
The tendency to overeat, feel fatigued and lethargic, oversleep, crave carbohydrates and gain weight are symptoms that are described as “atypical” in the literature on depression, but these are common in SAD. The prolonged duration of these depressions in SAD, usually between three to seven months, distinguishes SAD from the so-called holiday blues, which is a short-lived psychological reaction to stresses that typically occur around the holiday season. For more information, telephone counselling or referrals to mental health professionals for SAD, its diagnosis and treatment, or on other affective and anxiety disorders, the Depression and Anxiety Support Group can be contacted, Monday to Friday, between 8am and 7pm, and on Saturdays, between 8am and 5pm, on (011) 783 – 1474/6.
Studies have shown that during autumn and winter about 20% of the population is affected by fatigue, irritability, anxiety, weight gain, social withdrawal and a lack of alertness. About 75% of the people affected are women. The reason women are more vulnerable to the effects of the changing seasons is not well understood, but it may be hormonally related as it increases after puberty and decreases in the post-menopausal years.
To diagnose this disorder, doctors have to rely on patterns in the patient’s history. A family history of mood disorders, alcohol abuse and SAD itself are common in the first-degree relatives of the sufferer, so this suggests that seasonality, to some degree, is an inherited trait. Light deprivation has also been shown to be very important in the development of SAD. Light, like air and water, is essential to our well being. Natural light regulates our internal 24-hour biological clock that controls our alertness and energy. When dim indoor lighting, dark winters and shift work disrupt this body clock, our bodies get out of sync, causing lethargy and moodiness.
People living in the Northern Hemisphere are most affected by light deprivation, due to the long nights and short days of winter. According to Johannesburg psychiatrist Dr Michael Berk: “There has been no research in South Africa on this disorder, so the prevalence is not really known. Usually the further you get from the equator, the more cases of SAD you find, therefore in South Africa it shouldn’t be all that common.” Insufficient light due to the sky being frequently overcast, indoor working conditions, health and age related indoor confinement, shift work and travel across several time zones, however, can also cause SAD. Studies show that exposure to bright light, as opposed to ordinary room light, suppresses night-time melatonin production, implying that exposure to sunlight synchronizes human biological rhythms. This therefore leads to a treatment for SAD – using bright artificial light to therapeutically manipulate biological rhythms in humans.
For many people with SAD, light therapy should be regarded as a first-line treatment, as it has a high success rate and a high acceptance rate. It is essential though to have an ophthalmologic check-up first, to ensure that it is not ocular difficulties that are exacerbating the light deprivation. People with retinal problems should be cautious about using light therapy, as should people taking photosensitizing agents, because these may enhance the toxic effects of light on the retina.
Bright light therapy has a success rate of over 90% and leading medical centers worldwide have successfully treated SAD, sleep disorders, PMS, jet lag and shift work schedule adjustments.
Therapeutic light boxes are used, that are 20 to 50 times brighter than ordinary room light. Bright light, the brightness of which is measured in lux, enters the eye and suppresses the hormone melatonin. This sends a signal to your body clock setting its 24-hour rhythm. Research has shown that between 2 500 and 10 000 lux is needed to suppress melatonin and shift the body clock. Timed exposure to a bright light box can therefore reset the body clock thereby relieving the symptoms. The patient usually sits in front of the light unit at a prescribed distance while reading, eating, watching TV etc, only occasionally glancing at the light. Thirty minutes daily usually produces improvement, but treatment time can range from 15 minutes to 2 hours. Research has also shown that the timing of light exposure is critical. Light during the morning resets the body’s clock to an earlier hour, making waking easier, while evening light resets it to a later time. The most beneficial time for you will depend on whether you are a phase-advanced or phase-delayed type.
Although the effects of light therapy are often seen in the first week, recent evidence suggests that the anti-depressant effect increases over several weeks, so don’t give up if you don’t respond within the first few weeks of treatment. Some response would be expected within the third or fourth week though.
Light boxes are not available in South Africa, but according to Dr Berk, they can be constructed with a few fluorescent tubes. It is important to use the correct lux though and a psychiatrist should be consulted for the prescribed distance and duration of the therapy.
While light therapy is often free of side effects, the more common ones include eyestrain, headaches, irritability and insomnia, the last particularly if treatments are administered late at night. These latter symptoms may be part of a hypomanic or even manic episode induced by too much light exposure, although this is a very rare complication.
If the light therapy is unsuccessful in alleviating a SAD sufferer’s depressive symptoms, there are other options that can be tried. These are anti-depressant medications, stress management, exercise, and exposure to outdoor light.