Seasonal Affective Disorder

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Definition

Seasonal affective disorder (SAD) is a form of depression most often associated with the lack of daylight in extreme northern and southern latitudes from the late fall to the early spring.

Description

Although researchers are not certain what causes seasonal affective disorder, they suspect that it has something to do with the hormone melatonin. Melatonin is thought to play an active role in regulating the "internal body clock," which dictates when humans feel like going to bed at night and getting up in the morning. Although seasonal affective disorder is most common when light is low, it may occur in the spring, and it is then often called reverse SAD.

— Robert Scott Dinsmoor

A form of depression occurring at certain seasons of the year, especially when the individual has less exposure to sunlight.

A mood disorder characterized by mild depression and lethargy, apparently triggered by a reduction in the number of daylight hours in autumn and winter. It is often accompanied by intense cravings for sugary foods that might alleviate feelings of depression. SAD sufferers usually lose their cravings when exposed to special, bright artificial lighting for one or two hours each day.

A mood disorder associated with the shorter days and longer nights of autumn and winter. Symptoms include lethargy, depression, social withdrawal, and work difficulties.

Definition

Seasonal affective disorder (SAD) is a form of depression most often associated with lack of daylight in extreme northern and southern latitudes from the late fall to the early spring.

Description

Although researchers are not certain what causes seasonal affective disorder, they suspect that it has something to do with the hormone melatonin. Melatonin is thought to play an active role in regulating the "internal body clock," which dictates when humans feel like going to bed at night and getting up in the morning. Although seasonal affective disorder is most common when light is low, it may occur in the spring, which is often called reverse or spring-onset SAD. Recent research also indicates that SAD has a genetic factor; about 29% of cases in the United States run in families.

Causes & Symptoms

The body produces more melatonin at night than during the day, and scientists believe it helps people feel sleepy at nighttime. There is also more melatonin in the body during winter, when the days are shorter. Some researchers believe that excessive melatonin release during winter in people with SAD may account for their feelings of drowsiness or depression. One variation on this idea is that people's internal clocks may become out of sync during winter with the light-dark cycle, leading to a long-term disruption in melatonin release. Another possible cause of SAD is that people may not adjust their habits to the season, or sleep more hours when it is darker, as would be natural.

Seasonal affective disorder, while not an official category of mental illness listed by the American Psychiatric

Association, is estimated to affect 6% of the American population. Another 25 million Americans may have a mild form of SAD, sometimes called the "winter blues" or "winter blahs." The risk of SAD increases the further from the equator a person lives; one early study of SAD found a 1.4% incidence of the disorder among people living in Florida, compared with 9.7% among residents of New Hampshire. Other factors that influence the incidence and severity of SAD are sex and age. Women are more likely than men to develop SAD, but men with the disorder are more severely depressed than most women who have it. SAD appears to decrease in severity with age; the elderly have milder SAD symptoms than adolescents.

Comparative studies indicate that the incidence of SAD in the United States and Canada is about twice as high as in European countries at the same latitudes north of the Equator. These findings suggest that cultural factors are also involved in the disorder.

The symptoms of SAD are similar to those of other forms of depression. People with SAD may feel sad, irritable, or tired, and may find themselves sleeping too much. They may also lose interest in normal or pleasurable activities (including sex), become withdrawn, crave carbohydrates, and gain weight.

Diagnosis

Doctors usually diagnose seasonal affective disorder based on the patient's description of symptoms, including the time of year they occur. There is also a diagnostic questionnaire called the Seasonal Pattern Assessment Questionnaire, or SPAQ, used in all Canadian university hospitals and widely used in the United States to assess SAD patients.

Treatment

The first-line treatment for seasonal affective disorder is light therapy (also known as phototherapy). The most commonly used phototherapy equipment is a portable lighting device known as a light box. The box may be mounted upright to a wall or slanted downward toward a table. The patient sits in front of the box for a pre-prescribed period of time (anywhere from 15 minutes to several hours). Some patients with SAD undergo light therapy sessions two or three times daily, others only once. The time of day and the number of times treatment is administered depend on the physical needs and lifestyle of the patient. Light therapy treatment for SAD typically begins in the fall as the days begin to shorten, and continues throughout the winter and possibly the early spring.

The light from a slanted light box is designed to fall on the table supporting the box, so patients may look down to read or do other sedentary activities during therapy. Patients using an upright light box must face the light source (although they need not look directly into the light). The light sources in these light boxes typically range from 2,500 to 10,000 lux (in contrast, average indoor lighting is 300 to 500 lux; a sunny summer day is about 100,000 lux).

A recent British study suggests that dawn simulation, a form of light therapy in which the patient is exposed to white light of gradually increasing brightness (peaking at 250 lux after 90 min) may be even more effective in treating SAD than exposure to bright light. Dawn simulation is started around 4:30 or 5 o'clock in the morning while the patient is still asleep.

Patients with eye problems should see an ophthalmologist regularly both before and during light therapy. Because some UV rays are emitted by the light boxes used in phototherapy, patients taking photosensitizing medications and those who have sun-sensitive skin should consult with a health care professional before beginning treatment. Patients with medical conditions that make them sensitive to UV rays should also see a doctor before starting phototherapy.

Light therapy appears to be safe for most people. However, it can cause side effects of eyestrain, headaches, insomnia, fatigue, sunburn, and dry eyes and nose in some patients. Most of these effects can be managed by adjusting the timing and duration of light therapy sessions. A strong sun block and eye and nose drops can alleviate the others.

Recently, researchers have begun testing whether people who do not completely respond to light therapy can benefit from tiny doses of the hormone melatonin to reset the body's internal clock. Early results look promising, but the potential benefits must be confirmed in larger studies before this type of treatment becomes widely accepted.

Allopathic Treatment

Like other types of mood disorders, seasonal affective disorder may also respond to medication and psychotherapy. Common drugs prescribed for mood disorders are:

• Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft)
• Monoamine oxidase inhibitors (MAO inhibitors), such as phenelzine sulfate (Nardil) and tranylcypromine sulfate (Parnate)
• Lithium salts, such as lithium carbonate (Eskalith), often used in people with bipolar mood disorders, are often useful with SAD patients who also suffer from bipolar disorder (excessive mood swings; formerly known as manic depression)

A number of psychotherapy approaches are useful as well. Interpersonal psychotherapy helps patients recognize how their mood disorder and their interpersonal relationships interact. Cognitive-behavioral therapy explores how the patient's view of the world may be affecting mood and outlook.

A new treatment for SAD that is still in the experimental phase as of 2001 is the use of high-density negative air ionization.

Expected Results

Most patients with seasonal affective disorder respond to light therapy, dawn simulation, and/or antidepressant drugs. Others respond to sleeping more hours in a dark room. Some researchers estimate that as much as 9.5 hours of sleep are important in winter months and that getting more sleep will increase the person's levels of natural melatonin.

Resources

Books

Lam, Raymond, ed. Seasonal Affective Disorder and Beyond: Light Treatment for SAD and Non-SAD Conditions. Washington, DC: American Psychiatric Press, 1998.

Partonen, Timo, and Andres Magnusson, eds. Seasonal Affective Disorder: Practice and Research. Oxford, UK: Oxford University Press, 2001.

Peters, Celeste A. Don't Be SAD: Your Guide to Conquering Seasonal Affective Disorder. Calgary, Alberta: Good Health Books, 1994.

Rosenthal, Norman. Winter Blues: Seasonal Affective Disorder—What It Is and How to Overcome It. New York: Guilford Press, 1998.

Periodicals

Anderson, Janis L., and Gabrielle I. Warner. "Seasonal Depression." Harvard Health Letter (February 1996): 7-8.

Eagles, John M. "SAD—Help arrives with the dawn?" Lancet 358 (December 22, 2001): 2100.

Singer, Ethan A. "Seasonal Affective Disorder: Autumn Onset, Winter Gloom." Clinician Reviews 11 (November 2001): 49-54.

"Winter Depression: Seeing the Light." The University of California Berkeley Wellness Letter (November 1996): 4.

Organizations

National Depressive and Manic Depressive Association. 730 N. Franklin Street, Ste. 501, Chicago, IL 60610. (312) 642-0049.

National Institute of Mental Health. Mental Health Public Inquiries, 5600 Fishers Lane, Room 15C-05, Rockville, MD 20857. (301) 443-4513. (888) 826-9438. .

Society for Light Treatment and Biological Rhythms. 824 Howard Ave., New Haven, CT 06519. Fax (203) 764-4324. .

[Article by: Paula Ford-Martin; Rebecca J. Frey, PhD]

For more information on seasonal affective disorder, visit Britannica.com.

Light therapy lamp for Seasonal Affective Disorder

Seasonal affective disorder, also known as winter depression, is an affective, or mood, disorder. Most SAD sufferers experience normal mental health throughout most of the year, but experience depressive symptoms in the winter or summer. The condition in the summer is often referred to as Reverse Seasonal Affective Disorder.

Pathophysiology

Seasonal mood variations are believed to be related to light. An argument for this view is the effectiveness of bright light therapy.^[1] SAD is measurably present at latitudes in the Arctic region, such as Finland (64º 00´N) where the rate of SAD is 9.5%^[2] Cloud cover may contribute to the negative effects of SAD.^[3]

SAD can be a serious disorder and may require hospitalization. There is also potential risk of suicide in some patients experiencing SAD. One study reports 6-35% of sufferers required hospitalization during one period of illness.^[3] The symptoms of SAD mimic those of dysthymia or clinical depression. At times, patients may not feel depressed, but rather lack energy to perform everyday activities.^[1] Norman Rosenthal, a pioneer in SAD research, has estimated that the prevalence of SAD in the adult United States population is between about 1.5 percent (in Florida) and about 9 percent (in the northern US).^[3]

Various etiologies have been suggested. One possibility is that SAD is related to a lack of serotonin, and serotonin polymorphisms could play a role in SAD,^[4] although this has been disputed.^[5] Another theory is that melatonin produced in the pineal gland is the primary cause since there are direct connections between the retina and the pineal gland. Mice incapable of synthesizing melatonin appear to express "depression-like" behaviors, melatonin receptor ligands produce an antidepressant-like effect^[6] Subsyndromal Seasonal Affective Disorder is a milder form of SAD experienced by an estimated 14.3% vs. 6.4% of the U.S. population.^[7] The blue feeling experienced by both SAD and SSAD sufferers can usually be dampened or extinguished by exercise and increased outdoor activity, particularly on sunny days, resulting in increased solar exposure.^[8] Connections between human mood, as well as energy levels, and the seasons are well-documented, even in healthy individuals. Particularly in high latitudes (50°N or S) it is common for people to experience lower energy levels.^[8]

Treatment

Another type of light therapy lamp

There are many different treatments for seasonal affective disorder, including light therapies, medication, and ionized-air reception. Bright light treatments are common, however as many as 19% of patients stop use because of the inconvenience.^[2] Specially designed light, many times brighter than normal office lighting, is placed near the sufferer, and has proven to be effective at doses of 2500- 10,000 lux.^[7] Most treatments use 30-60 minute treatments, however this varies depending on the situation. The sufferer sits a prescribed distance, commonly 30-60 cm, in front of the box with her/his eyes open but not staring at the light source.^[2] Many patients use the light box in the morning, however it has not been proven any more effective than any other time of day.^[7] Discovering the best schedule is essential because up to 69% of patients find it inconvenient.^[2] Dawn simulation has also proven to be more effective in some studies, there is an 83% better response when compared to bright light.^[2] When compared in a study to negative air ionization however, bright light was proven to be 57.1% effective vs. dawn simulation, 49.5%.^[9] Patients using light therapy can experience improvement during the first week, but increased results are evident when continued throughout several weeks.^[2] Most studies found it effective without use year round, but rather as a seasonal treatment lasting for several weeks until frequent light exposure is naturally obtained.^[1] SSRI (selective serotonin reuptake inhibitor) antidepressants have proven effective in treating SAD. Bupropion is also effective as a prophylactic.^[3] Effective antidepressants are fluoxetine, sertraline, or paroxetine.^[1][10] Both fluoxetine and light therapy are 67% effective in treating SAD according to direct head-to-head trials.^[1] Negative air ionization, involving the release of charged particles into the sleep environment, has also been found effective with a 47.9% improvement.^[9] Depending upon the patient, one treatment (ie. lightbox) may be used in conjunction with another therapy (ie. medication).^[1]

Throughout the world

Scandinavia

Winter depression (or winter blues) is a common slump in the mood of Scandinavians. Doctors estimate that about 20% of all Scandinavians are affected, and it seems to be genetically heritable.^{[citation needed]} It was first described by the 6th century Goth scholar Jordanes in his Getica where he described the inhabitants of Scandza (Scandinavia).^[11] There are words in Icelandic and Swedish that directly describe Seasonal Affective conditions. The Icelandic word is "skammdegisthunglyndi". "Skamm" means short, "degi" is day, "thung" is heavy and "lyndi" means mood although there is some argument as to how long the word existed as the earliest records indicate it appeared in the late 1800s in print. ^[12]

United States

In the United States, a diagnosis of seasonal affective disorder was first proposed by Norman E. Rosenthal, MD in 1984. Rosenthal wondered why he became muggish during the winter after moving from sunny South Africa to New York. He started experimenting increasing exposure to artificial light, and found this made a difference. In Alaska it has been established that there is an SAD rate of 8.9%, and an even greater rate of 24.9%^[13] for subsyndromal SAD.

SAD and bipolar disorder

Most people with SAD experience unipolar depression, but as many as 20% may have or go on to develop a bipolar or manic-depressive disorder.^[14] In these cases, persons with SAD may experience depression during the winter and hypomania in the summer.

Famous sufferers

• Winston Churchill, Abraham Lincoln, and Gustav Mahler^[15]
• Natalie Imbruglia, a famous Australian singer, suffered from SAD during a longer stay in London, England.^[16]
• Science fiction-fantasy author Barbara Hambly suffered with undiagnosed SAD for many years.^[17]

See also

• Depression (mood)
• Circadian rhythm sleep disorder

References

1. ^ ^{a b c d e f} Lam, RW; Levitt AJ, Levitan RD, Enns MW, Morehouse R, Michalak EE, Tam EM (2006). "The Can-SAD Study: a randomized controlled trial of the effectiveness of light therapy and fluoxetine in patients with winter seasonal affective disorder". American Journal of Psychiatry 163 (5). 16648320. Retrieved on 2007-05-12. 
2. ^ ^{a b c d e f} Avery, D H; Eder DN, Bolte MA, Hellekson CJ, Dunner DL, Vitiello MV, Prinz PN (2001). "Dawn simulation and bright light in the treatment of SAD: a controlled study". Biological Psychiatry 50 (3): 205-216 = id = 11513820. Retrieved on 2007-05-05. 
3. ^ ^{a b c d} Modell, Jack; Rosenthal NE, Harriett AE, Krishen A, Asgharian A, Foster VJ, Metz A, Rockett CB, Wightman DS (2005). "Seasonal affective disorder and its prevention by anticipatory treatment with bupropion XL Biological Psychiatry" 58 (8): 658-667. 16271314. 
4. ^ Johansson, C; Smedh C, Partonen T, Pekkarinen P, Paunio T, Ekholm J, Peltonen L,Lichtermann D, Palmgren J, Adolfsson R, Schalling M (2001). "Seasonal affective disorder and serotonin-related polymorphisms". Neurobiology of Disease 8 (2): 351-357. 11300730. Retrieved on 2007-05-05. 
5. ^ Johansson, C; Willeit M, Levitan R, Partonen T, Smedh C, Del Favero J, Bel Kacem S, Praschak-Rieder N,Neumeister A, Masellis M, Basile V, Zill P, Bondy B, Paunio T, Kasper S, Van Broeckhoven C, Nilsson LG,Lam R, Schalling M, Adolfsson R. (2003). "The serotonin transporter promoter repeat length polymorphism, seasonal affective disorder and seasonality". Psychological Medicine 33 (5): 785-792. 12877393. Retrieved on 2007-05-05. 
6. ^ Uz, T; Manev, H (2001). "Prolonged swim-test immobility of serotonin N-acetyltransferase (AANAT)-mutant mice". Journal of Pineal Research 30: 166-170. 11316327. 
7. ^ ^{a b c} Avery, D. H.; Kizer D, Bolte MA, Hellekson C (2001). "Bright light therapy of subsyndromal seasonal affective disorder in the workplace: morning vs. afternoon exposure". Acta Psychiatrica Scandinavica 103 (4): 267-274. 11328240. Retrieved on 2007-05-12. 
8. ^ ^{a b} Leppämäki, Sami; Haukka J, Lonnqvist J, Partonen T (2004). "Drop-out and mood improvement: a randomised controlled trial with light exposure and physical exercise". BMC Psychiatry 4 (22). 15306031. Retrieved on 2007-05-12. 
9. ^ ^{a b} Terman, M.; Terman, J.S. (2006). "Controlled Trial of Naturalistic Dawn Simulation and Negative Air Ionization for Seasonal Affective Disorder". American Journal of Psychiatry 163 (12): 2126-2133. 17151164. Retrieved on 2007-05-12. 
10. ^ Moscovitch, A; Blashko CA, Eagles JM, Darcourt G, Thompson C, Kasper S, Lane RM (2004). "A placebo-controlled study of sertraline in the treatment of outpatients with seasonal affective disorder". Psychopharmacology 171: 390-397. Retrieved on 2007-05-12. 
11. ^ Jordanes, Getica, ed. Mommsen, Mon. Germanae historica, V, Berlin, 1882.
12. ^ [1]
13. ^ Seasonal Affective Disorder and Latitude
14. ^ SAD and depression
15. ^ "Winter Blues", p.294 Norman E. Rosenthal
16. ^ Interview with Natalie Imbruglia 17th June 2005
17. ^ Andromeda Spaceways interview with Barbara Hambly, discusses SAD

External links

Resources

• Seasonal Affective Disorder at the Open Directory Project
• List of academic articles discussing season affective disorder

Organizations

• The Seasonal Affective Disorder Association (SADA) (UK-based charitable organisation)

Articles

• Getting SAD Is More Than Having The Blues (January 25, 2007). Retrieved on 2007-07-17.
• Ivry, Sara. "Seasonal Depression Can Accompany Summer Sun", August 13, 2002. Retrieved on 2007-07-17.  (about reverse-seasonal affective disorder)

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