Seasonal Affective Disorder

Seasonal Affective Disorder is classified as a sub-type of Major Depressive Disorder which is primarily related to the changing seasons. The onset of SAD varies predictably over the course of the year; usually during the fall and winter months and less rarely in spring and summer. The reduced level of sunlight in the fall and winter seasons has been highly associated with SAD which essentially disrupts the body's internal clock and lead to feelings of depression. Changes in levels of neurotransmitters such as Serotonin and Melatonin also affect the mood and sleep patterns of the affected individual.

The nature and severity of SAD varies from person to person. The symptoms usually start in the autumn or winter and tend to improve in the spring. The classic symptoms of SAD include oversleeping, daytime fatigue, carbohydrate craving, and weight gain.

1. Oversleeping: People with SAD tend to feel the need to sleep more during the wintertime.
2. Daytime Fatigue: Individuals with SAD often lack energy and motivation and feel hopeless and agitated. They feel depressed most of the day, lose interest in daily activities and have a greater tendency of nodding off at work.
3. Carbohydrate Craving: SAD can produce a strong craving for complex carbohydrates such as bread and pasta which eventually causes the levels of an amino acid, tryptophan to rise in the brain. This in turn causes the release of serotonin, which boosts mood. In effect, people with SAD use carbohydrates as a kind of medication—and a bigger waistline is a common side effect.
4. Weight Gain: Like depression in general, SAD increases appetite in most people. Sixty-five percent of people with the disorder report being hungrier during the colder, darker months. This voracious appetite is speculated to be a biological response to a seasonal drop in serotonin, a neurotransmitter that’s associated with mood and helps to control hunger. The increased appetite and a higher carbohydrate consumption often lead to weight gain in most individuals.

Phototherapy is a type of bright-light therapy that is administered to patients with SAD, especially in the winter. Exposure to natural or artificial light suppresses the brain’s secretion of melatonin. The eyes are exposed to atleast 2500 lx of artificial visible light at eye level (distance of about 1 meter) first thing in the morning (Terman et al., 1989). This light is emitted in high intensity through specially designed light boxes. To give an estimate, there is around 100 lx in a house, 2000 lx outside on a rainy winter day or 10,000 lx in direct sunshine (Partonen, 1998). Patients receive daily administration of bright light therapy usually in their own homes (Terman et al., 1989). Generally, higher intensities and shorter exposures yielded best response rates. A patient shows response to this treatment within 1-2 weeks and after this point, exposure is maintained for 5 times a week for the duration of winter. Side effects of this treatment can include eyestrain and headaches, but they are usually not serious (Partonen, 1998).

Drug Therapies Antidepressants may be given to treat SAD. The antidepressant drugs administered for SAD include sertraline, fluoxetine and moclobemide, which are selective serotonin-reuptake inhibitors (SSRIs). Some studies suggest that since tryptophan is a precursor for serotonin and melatonin, it may be beneficial in conjunction with phototherapy (Rodin and Thompson, 1997)

Preliminary research suggests that cognitive behavioral therapy can be useful in improving cognitive and behavioral for individuals with seasonal affective disorder. This type of therapy aids in changing patients’ automatic thoughts, dysfunctional attitudes, withdrawal and rumination. CBT is also effective in preventing relapse since the effects of CBT persist even beyond formal sessions (Rohan et al., 2004).

Phototherapy, psychotherapy and drug therapies can be combined, but there remains the risk of over arousal. Combined treatment is ideal for patients who have no response to phototherapy or drug therapy alone (Rodin and Thompson, 1997).

• Aerobic exercise
• Sleep deprivation
• Increase the amount of light at home
• Meditation
• Stress management
• Relocate to area with more sun

Partonen, T. (1998) Seasonal affective disorder. The Lancet, 352(9137): 1369-1374.

Rodin, I. and Thompson, C. (1997) Seasonal Affective Disorder. Advances in Psychiatric Treatment, 3: 352-359.

Rohan et al. (2004). Cognitive-behavioral therapy, light therapy, and their combination in treating seasonal affective disorder. Journal of Affective Disorders, 80: 273-283.

Terman et al. (1989). Light Therapy for Seasonal Affective Disorder: A Review of Efficacy. Neuropsychopharmacology, 2(1): 1-22.