SAD Article - About SAD
In the early 1980s, Herb Kern, a research engineer, who thought that his annual cycle of depression might be caused by the shorter and duller daylight hours in winter, approached doctors working at the National Institute for Mental Health in Bethesda, USA. They proposed a treatment where he was exposed to light, equivalent to summer sunlight, for several hours each day. By the fourth day his symptoms had virtually disappeared (Lewy et al 1982). This was the start of our acknowledging the condition that has come to be known as Seasonal Affective Disorder or SAD.
Since the 1980’s, most of the interest in SAD has been stimulated by its response to exposure to bright artificial light. Clinical consensus guidelines are now recommending light therapy as 'a first-line treatment for SAD' (Lam & Levitt, 1999). Indeed, the treatment of SAD is almost exclusively associated with light therapy, in fact, it has been proposed that response to phototherapy may be a diagnostic criteria for SAD (Smyth, 1990).
In most animals and humans, the desire to sleep is brought on by the secretion of a hormone called melatonin. In the evening the pineal gland reacts to the diminishing levels of daylight and begins producing melatonin. Melatonin is then released into the blood and flows through the body making us drowsy. Its secretion peaks in the middle of the night during our heaviest hours of sleep. In the morning, bright light shining into the eye reaches the pineal gland, which reacts by switching off the production of melatonin, thus removing the desire to sleep.
The pineal gland communicates with the rest of the hormonal system. Consequently melatonin production also influences the functioning of other parts of the body. During darkness and sleep, melatonin modifies the secretion of hormones from organs such as the pituitary gland, the ‘master gland’ of the hormonal system. The pituitary in turn regulates the secretion of hormones controlling growth, milk production, egg and sperm production. It also regulates the action of the thyroid gland, which is concerned with metabolism, and the adrenal glands, which control excretion of the body's waste. Further, it has been shown that light also effects levels of serotonin and dopamine neurotransmitters. The latter are connected with the Limbic system and the hypothalamus, which effects mood, emotion and autonomic systems, such as digestion. Therefore, fluctuations in light and darkness according to the seasons of the year influence rhythms of growth, reproduction and behaviour in animals and humans alike.
There are four classic symptoms experienced by SAD sufferers.
- Extreme fatigue and lack of energy.
- Greater need for sleep and sleeping more than usual.
- Changes in appetite, especially cravings for carbohydrates and sweets, which can often lead to weight gain.
- Depression.
Further, there are a number of other symptoms, which may be experienced by some sufferers.
- Mood - sufferers tend to feel sad and low. They're often less interested in life and find it difficult to cope with everyday tasks. They may be irritable and short with friends and colleagues.
- Sleep - sleep disturbance is common in SAD but varies from case to case - feeling excessively sleepy during the day is a common feature, and sleep is less satisfying.
- Anxiety - tension, inability to cope with stress, phobias.
- Loss of libido - decreased interest in sex.
- Menstrual difficulties - pre-menstrual tension may be worse.
- Feelings of hopelessness.
- Increased sensitivity to pain - headaches, muscle and joint pain.
- Other physical ailments - constipation, diarrhoea, palpitations.
Despite minor differences, research from different parts of the world has shown that SAD strikes regardless of race, class or occupation (Han et al, 2000; Ozaki et al, 1995; Smyth, 1990). It is generally believed that the most common ages of onset are in the twenties and thirties, however, cases of childhood SAD have been reported (Rosenthal et al, 1986; Swedo et al, 1995) and successfully treated (Swedo et al, 1997; Giedd et al, 1998). In addition, Low & Feissner (1998) investigating prevalence of SAD in college students found prevalence rates for SAD (13.2%) and S-SAD (a milder form of SAD) combined (19.7%), these are broadly in line with other population estimates. They also found that the prevalence of SAD was higher in females, which was consistent with findings from previous research.
Several qualitative reviews have concluded that light therapy is an effective treatment for SAD, with response rates of 60% to 90% in controlled studies (Eastman et al 1998; Lamberg, 1998; Partonen & Lonnqvist, 1996; Tam et al, 1996). It has been found that between 75-85% of people suffering from SAD and S-SAD (a milder form of SAD) feel better after 3-4 days of consistent light therapy. Some individuals feel better immediately after their first dose, even within 20 minutes of exposure, while others may need several days (Terman et al, 1998). Two meta-analyses also confirm the efficacy of light therapy against plausible placebo controls (Terman et al, 1989; Lee & Chan, 1999). Light therapy has been also found to be superior to conventional anti-depressants in the treatment of SAD. Ruhrmann et al (1998) investigated whether fluoxetine (Prozac™) has antidepressant effects comparable to bright light in the treatment of seasonal affective disorder. They concluded that the remission rate in those patients using light therapy were far superior. Indeed, some psychiatrists are now suggesting that light therapy may be effective in treating nonseasonal, classical depression (Beauchemin & Hays, 1997; Benedetti et al 2001; McEnany & Lee, 1997) and patients in long term care (Lyketsos et al 1999).
Another possible application for light therapy is in the treatment of PMS. The symptoms of PMS are similar to those of SAD & S-SAD - depression, fatigue, irritability anxiety, over eating etc, and occur in women every month. Maskall et al (1997) suggest that patients with late luteal phase dysphoric disorder (LLPDD) have substantial seasonal patterns in mood and pre-menstrual symptoms. Lam et al (1999) found that bright light therapy significantly reduced depression and pre-menstrual tension scores during the symptomatic luteal phase. These results suggest that bright light therapy is an effective treatment for LLPDD.
Individuals who have more severe difficulty with the timing of their sleep-wake cycle may have either Delayed Sleep Phase Disorder (difficulty falling sleep and the urge to sleep late) or Advanced Sleep Phase Disorder (tiring too early and waking too early). Both conditions can be treated with bright light (Terman et al, 1995).
Several studies have shown that light therapy can be used very effective in alleviating symptoms of jet lag (Smyth, 1990). Indeed, shift workers often have symptoms of mild depression, fatigue, difficulty with sleeping and problems with attention and alertness. Studies have shown that these symptoms may also be significantly reduced through the use of light therapy (Czeisler et al, 1990; Stewart et al, 1995).
Studies have shown that growth rates in children are affected by the seasons. For example, surveys carried out in Germany, Sweden and Scotland show that height and weight increase is more predominant in the spring and early summer (Smyth, 1990). In many countries the rate of conception peaks in the summer when the hours of daylight are longest. In numerous trials the seasons have been seen to influence the timing and duration of sleep, pain threshold, alertness, eating habits, mood, the onset of menstruation and sexual activity.
Light therapy has been shown to be a successful, non-invasive therapy without significant side effects, within many spheres of our lives. Indeed, a Canadian study has revealed improvements in academic achievement, attendance records and growth rates in the classroom when children were treated with bright light. It also showed a reduction in tooth decay. Another study at Cornell University showed that working under very bright lighting helped to reduce perceptual fatigue. The positive implications and applications of light therapy are only just being recognised; it is clear that in the future we will need to re-think how we use lighting within our schools, workplaces, hospitals and homes.
For more information on SAD & S-SAD please visit: http://www.britebox-sad-lamps.com/seasonal-affective-disorder.php
SAD References
Beauchemin, K.M. & Hays, P. (1997). Phototherapy is a useful adjunct in the treatment of depressed in-patients. Acta-Psychiatrica-Scandinavica, 95(5), 424-427.
Benedetti, F., Colombo, C., Barbini, B., Campori, E., & Smeraldi, E. (2001). Morning sunlight reduces length of hospitalization in bipolar depression. Journal of Affective Disorders, 62(3), 221-223.
Cseisler, CA., Johnson, MP., Duffy, JF., Brown, EN., Ronder, JM. (1990). Exposure to bright light and darkness to treat physiologic maladaptation to nightwork. New England Journal of Medicine, 322, 1253-1259.
Eastman, C.I., Young, M.A., Fogg, L.F., Liu, L. & Meaden, P.M. (1998). Bright light treatment of winter depression: A placebo-controlled trial. Archives of General Psychiatry, 55(10), 883-889.
Han, L., Wang, K., Du, Z., Cheng, Y., Simons, JS. & Rosenthal, NE. (2000). Seasonal variations in mood and behavior among Chinese medical students. American Journal of Psychiatry 157(1), 133-135.
Lam, RW. & Levitt, AJ. (1999). Canadian consensus guidelines for the treatment of seasonal affective disorder. Vancouver: Clinical & Academic Publishing.
Lee, TM. & Chan, CC. (1999). Dose-response relationship of phototherapy for seasonal affective disorder: a meta-analysis. Acta Psychiatrica Scandinavica, 99, 315-23.
Lewy, A., Kern, H., Rosenthal, N., Wehr, T. (1982). Bright artificial light treatment of a manic-depressive patient with a seasonal mood cycle. Journal of Affective Disorders, 14, 13-19.
Low, K.G. & Feissner, J.M. (1998). Seasonal affective disorder in college students: Prevalence and latitude. Journal of American College Health, 47, 135-137.
Lyketsos, C.G., Veiel, L.L., Baker, A. & Steele, C. (1999). A randomized, controlled trial of bright light therapy for agitated behaviors in dementia patients residing in long-term care. International Journal of Geriatric Psychiatry, 14(7), 520-525.
Maskall, D.D., Lam, R.W., Misri, S., Carter, D., Kuan, A.J., Yatham, L.N. & Zis, A.P. (1997). Seasonality of symptoms in women with late luteal phase dysphoric disorder. American Journal of Psychiatry, 154(10), 1436-1441.
McEnany, GW. & Lee, KA. (1997). Effects of phototherapy in women with non-seasonal/non-bipolar major depression. Sleep Research, 26, 294.
Ozaki, N., Ono, Y., Ito, A. & Rosenthal, NE. (1995). The prevalence of seasonal difficulties among Japanese civil servants. American Journal of Psychiatry 152:1225-1227.
Partonen, T. & Lonnqvist, J. (1996). Prevention of winter seasonal affective disorder by bright-light treatment. Psychological-Medicine, 26(5): 1075-1080.
Rosenthal NE, Carpenter CJ, James SP, Parry BL, Rogers SLB. & Wehr TA. (1986). Seasonal affective disorder in children and adolescents. American Journal of Psychiatry 143, 356-358.
Ruhrmann S., Kasper S., Hawellek B., Martinez B., Hoflich G., Nickelsen T. & Moller HJ. (1998) Effects of fluoxetine versus bright light in the treatment of seasonal affective disorder. Psychological Medicine, 28(4), 923-933.
Smyth, A. (1990). Seasonal Affective Disorder. London: Harper Collins.
Swedo SE, Pleeter JD, Richter DM, Hoffman CL, Allen AJ, Hamburger SD, Turner E, Yamada EM, Rosenthal NE. (1995). The rates of seasonal affective disorder in children and adolescents. American Journal of Psychiatry 152(7), 1016-1019.
Tam, EM., Lam, RW., Levitt, AJ. (1995). Treatment of seasonal affective disorder. Canadian Journal of Psychiatry, 40, 457-66.
Terman, M., Terman, JS., Quitkin, FM., McGrath, PJ., Stewart, JW., Rafferty, B. (1989). Light therapy for seasonal affective disorder. A review of efficacy. Neuropsychopharmacology, 2, 1-22.
Terman, M., Lewy, AJ., Djik, DJ., Boulos, Z., Eastman, CI. & Campbell, SS. (1995). Light treatment for sleep disorders: consensus report. Journal of Biological Rhythms, 10, 135-47.
Terman, M., Lewy, AJ., Djik, DJ., Boulos, Z., Eastman, CI. & Campbell, SS. (1995). Light treatment for sleep disorders: consensus report. Journal of Biological Rhythms, 10, 135-47.
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