How to Cope with Seasonal Affective Disorder

SAD seasonal affective disorder

Seasonal affective disorder (SAD) is a form of depression that occurs in the fall and winter months.

Seasonal Affective Disorder (SAD)

During these times, shorter days lead to decreased sun exposure. This affects circadian rhythms and how the body regulates certain hormones. People living in northern latitudes may be at higher risk for the condition because of less sun exposure to these regions. Resolution of seasonal affective disorder is often spontaneous as days lengthen in the spring and summer. The prevalence of the condition is as high as 9.7% in the general population.

Melatonin and Mood

The pineal gland of the brain makes melatonin, a hormone responsible for regulating sleep-wake cycles. Darkness stimulates the gland to produce melatonin and light decreases production of the hormone. Levels of melatonin are naturally highest in the midday to evening hours. As the days get shorter in the fall and winter, melatonin production changes, produced earlier or later in the day.

The Melatonin-Serotonin Relationship

Increased amounts of melatonin decrease the amount of serotonin in the body, a hormone used as a building block for melatonin production. Seasonal variations in serotonin occur in healthy individuals as well as those suffering from seasonal affective disorder. Mood disorders such as depression and anxiety are associated with decreases in serotonin. For this reason, medications and other therapies that increase serotonin have been targeted as treatments for seasonal affective disorder.

Light Therapy Decreases Melatonin Production

Exposure to artificial sunlight decreases melatonin production during the day and improves symptoms of seasonal affective disorder. Though unregulated by the FDA, commercial light boxes can help. Light from different color spectra such as white, red, blue/green/yellow, or even full spectrum light show benefits for the condition. For safety reasons, these boxes remove UV light to avoid possible harm to the skin and eyes.

The quantity and the duration of lux exposure needs to be tailored to a person’s symptoms. A common effective dosage is 5,000 lux per day. Light boxes can administer short high-intensity bursts (10,000 lux over 30 minutes) or longer low-intensity treatments (2,500 lux over 2 hours). Light therapy given earlier in the day may be more effective in simulating the natural variations of the melatonin cycle.

Since light must stimulate receptors in the eye to affect melatonin production, users must place themselves beside the light box so that light enters the eye. Take care to avoid looking directly into the light source to minimize eye strain or headaches that could occur with the intensity of light.

Effectiveness of Light Therapy

Light therapy and antidepressant medications have similar effectiveness in the treatment of seasonal affective disorder. Light therapy leads to remission rates ranging from 47% to 79% whereas medication ranges from 43% to 62%. Combining the two treatment options could help but we need a definitive study to know for sure.

Signs and symptoms of depression may include lack of interest in activities, fatigue, impaired concentration, irritability, decreased appetite, and sleep disturbance. You can monitor yourself for symptoms, but you may need to ask a healthcare provider for help. They can guide to the best treatments for your seasonal affective disorder.

 

References

Acta Psychiatrica Scandinavica: An overview of epidemiological studies on seasonal affective disorder, https://doi.org/10.1034/j.1600-0447.2000.101003176.x

American Journal of Psychiatry: The Efficacy of Light Therapy in the Treatment of Mood Disorders: A Review and Meta-Analysis of the Evidence, https://doi.org/10.1176/appi.ajp.162.4.656

Current Pharmaceutical Design: Circadian  rhythms, melatonin and depression, https://doi.org/10.2174/138161211796197188

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