Seasonal Affective Disorder

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Seasonal Affective Disorder: A Hidden Disorder

Every person experiences seasonal changes in mood and behavior to a different degree, ranging from normal to extreme. People with extreme degrees of seasonal changes in mood and behavior are in fact suffering from seasonal affective disorder (SAD) [5]. I have distinguished such a change in my mood and behavior as the winter season came around this year. I usually experience increased duration of sleep and decreased energy in the winter time, and I have reasoned in the past that such changes were due to the cold temperature. Because the temperature was colder, I reasoned that my body was working harder to maintain homeostatic body temperature, thus needing more rest in the winter time. Although I slept more than my peers, I did not find this particularly problematic because I have learned that everybody has different sleep durations. However, I came to understand that my symptoms of depressed mood, desire to avoid social contact, decreased energy and lack of motivation were not normal, especially this year when I cried for half an hour about nothing. As I cried, I tried to convince myself (using the I-function, my storyteller) that there was no reason to cry, but I could not help myself from feeling depressed. The I-function, which is part of the nervous system involved in conscious thought that allows us to interpret an experience, noticed that something was wrong; however, the I-function could not change how I was feeling. As I found the I-function to be ineffective in controlling my own behavior, I recognized that I was probably suffering from an actual disorder—SAD.

            Knowing that various disorders of the brain present themselves in behavior, and that behavior could also influence the brain, it can be inferred that there must be steps that can be taken to ameliorate the symptoms of SAD. With this knowledge in mind, I wanted to learn about SAD and find a way in which SAD symptoms could be treated through changes in behavior through research. Although people have been aware of the indicators of SAD for 150 years, it was only recognized as a disorder in the early 1980s [1]. The delay in this recognition as a disorder is due to the similarity in SAD's symptoms to other types of depression.

Originally, the disorder was defined as a depression that developed during autumn or winter that remitted for at least two successive years [5].  However, two types of SAD have been recognized since SAD was first termed: winter SAD and summer SAD [5].  The two subtypes of SAD differ in terms of when its symptoms appear during the year, and winter SAD occurs more frequently than summer SAD [5].  My paper is about winter SAD, and therefore SAD in this paper will be in reference to winter SAD. Also, symptoms that do not impair function to a great extent are called subsyndromal SAD [5].  About 4 to 6 percent have winter SAD; another 10 to 20 percent have subsyndromal SAD [4].

Symptoms of SAD include depressed mood and typical depressive symptoms such as increased duration of sleep, increased appetite, weight gain, and carbohydrate craving [5]. Other general symptoms of depression include reduced interest or pleasure, fatigue or loss of energy, feelings of worthlessness or excessive inappropriate guilt, reduced ability to think or concentrate, indecisiveness, and thoughts of death [1]. In comparison to patients with other types of depression, SAD patients have fewer suicidal thoughts but experience a worsening of mood in the morning [5]. These various symptoms usually begin during autumn, usually in September to November, depending on the latitudes of residence [5]. If SAD is left untreated, the symptoms last until the following spring, and some do not recover completely before the early summer [5]. In the summer, some experience reversal of their symptoms such as increased libido, improved social activity and energy, and decreased need for sleep, reduced appetite, and loss of weight [5].

With such a wide array of symptoms, it makes sense that SAD patients frequently find disability at work and in social relations. Even though depressive symptoms and depressed mood are rarely severe enough to require absence from work, SAD patients often experience disability as they cannot concentrate and are tired [5]. Their work performance is detrimentally affected. Typically, SAD occurs between the ages of 20 and 30 years old, but it has also been observed in children who chronically present fatigue, irritability, sleep inertia, and school problems [5]. They tend to attribute the cause of their problems to the external world (of family and school) rather than having insight into their symptoms [5]. As a result of the situations SAD presents at the workplace and school, SAD patients are more likely to be distressed by the decreased activity and fatigue than by the mood changes, and therefore will often initially seek the help of a physician rather than a psychiatrist [5].

            In the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), SAD is recognized as a form of either bipolar or recurrent major depressive disorder with a seasonal pattern of major depressive episodes [5]. DSM-IV describes SAD as a regular appearance of the major depressive episode in the autumn or winter, excluding cases in which there is an obvious effect of a seasonal-related psychosocial stressor [5]. For example, a seasonal-related psychosocial stressor could be recurring unemployment on the part of the patient every winter. SAD is described as a cycle of change from depression to mania, which is characteristic of a bipolar disorder [5]. However, SAD differs from bipolar disorder in that the change occurs with changes in season; depression appears in autumn or winter and disappears in the spring. If this cycle of change has occurred in the past 2 years and if seasonal major depressive episodes outnumber the non-seasonal major depressive episodes over a lifetime, then the person is diagnosed with SAD [5].

A genetic component is evidenced by an American study published in 1999, which found that 13-17% of people who develop SAD have an immediate family member with the disorder [3]. Twin studies by Madden and Jang have revealed that genes may influence the tendency to experience seasonal changes in mood and behavior [5]. Although genes have much influence on one’s susceptibility to SAD, much of how it occurs or it continues depends on one’s behavior.

While lifestyle is more of a choice, composed of various behaviors, circadian rhythms are not and are affected by the lifestyles we choose. Seasonally varying patterns of weather and durations of sunlight in combination with hectic lifestyles can disrupt human circadian rhythms [3]. Circadian rhythms are also known as biological clocks that help to control daily hormonal and behavioral rhythms, such as our core body temperature, cortisol ( the stress hormone),  and melatonin rhythms, sleep/wake cycle, subjective alertness and performance levels [6].  Our biological clocks are regulated by the light our bodies receive from the sun, and when we do not receive the light needed to regulate our bodies, we are faced with symptoms of SAD [6].

As previously stated, people’s lifestyles can be a factor in causing SAD. For instance, many college students pull all-nighters to finish a project, a paper, or to study for an exam. By doing so, they are unlikely to receive proper morning light and hinder their biological clocks from producing hormones appropriate to wake up and feel active [6]. Sleep problems and mood problems are the results of staying up late.  Lack of light causes an increase in the production of melatonin (the hormone that makes us sleepy at night), and a reduction of serotonin, the lack of which causes depression [3].  But active, energetic hormones are produced when the reception of light is appropriate for the biological clock to be regulated normally. Therefore, behavior that will maximize exposure of light is likely to abate the symptoms of SAD. Behavior such as getting up early to increase the amount of time to light exposure and travelling to latitudes nearer the equator are reported to see remission or diminished symptoms of SAD. In fact, 94% of patients that have travelled to latitudes nearer the equator have reported in abatement of symptoms [5].

According to Michael Terman, Ph.D., director of the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center in New York, the best treatment currently available is bright light therapy, since it helps to reset the body’s internal clock without the use of drugs [2].  Research that demonstrated a direct relationship between the exposure of ordinary room light (less than 500lx) and altered circadian and seasonal rhythms in animals led to the development of light therapy [5]. Through light therapy, nocturnal melatonin secretion is suppressed in the circadian cycle. Although antidepressants that increase the presence of serotonin in the brain could be used to treat SAD, it is recommended that light therapy be used instead, since antidepressants have a strong, sedating component [5]. Bright light therapy treatment varies case by case, but in general, the treatment involves sitting in front of a light box for about 30 minutes every day. This treatment process may not be friendly to a busy schedule, and therefore many have turned to antidepressants, even though antidepressant medication requires four to six weeks to respond compared to the four to seven days required for light therapy to take effect [2]. In addition, side-effects such as eyestrain, headache, nausea, agitation, and insomnia with light therapy are briefer than with antidepressants [2]. Thusly, light therapy is the best treatment available. There are other forms of treatments besides drugs and light therapy, but they lack the necessary scientific evidence to support their efficacy. Such treatments include high-density ions, hypericum, and exercise [5]. Although these types of treatment are found to be helpful, further research is needed to conclusively validate them as effective alternative treatments [5].

            Overall, I have learned that the best way to deal with SAD is to change my lifestyle. Since I can recognize an onset of SAD in winter, I can expose myself to more sunlight by waking up earlier in the day and by having a regular sleep schedule that would not disrupt my circadian rhythm. Hopefully, these changes in behavior will affect my brain and reduce the symptoms of SAD. In the hope of eradicating the disorder in the future, SAD should be made well-known to help SAD patients recognize their disorder readily. Information about SAD and other types of depression should be made available in the workplaces and schools. With recent stories of suicides in the media, especially of college students, I cannot help but wonder how many of those who committed/attempted suicides should have been diagnosed with SAD or other types of depression. Like me, they probably noticed that their I-functions did not work to overcome their disorders.



[1] CBC News In Depth: Mental health. (n.d.). In - Canadian News Sports Entertainment Kids Docs Radio TV. Retrieved May 1, 2009, from

[2] Consumer Reports Health. (n.d.). In Find Product Reviews and Ratings from Consumer Reports. Retrieved May 1, 2009, from

[3] - Seasonal Affective Disorder | SAD | Winter Blues - UK Voluntary Organisation providing Information, Advice and Answers. (n.d.). Retrieved May 1, 2009, from

[4] Seasonal Affective Disorder - March 1, 2000 - American Academy of Family Physicians. (n.d.). In Home Page -- American Academy of Family Physicians. Retrieved May 1, 2009, from

[5] Seasonal affective disorder practice and research. (2001). Oxford: Oxford UP.

[6] SpringerLink - Journal Article. (n.d.). In SpringerLink Home - Main. Retrieved May 1, 2009, from



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