SAD Light Therapy

SAD Light Therapy

SAD Light Therapy

Seasonal affective disorder is common during winter
Seasonal affective disorder is common during winter

Seasonal Affective Disorder (SAD) is a mood disorder that can affect people most commonly during the winter months when the sun exposure is at its lowest level. This mood altering disorder has also been linked to deficiencies in vitamin D as well as the sun’s influence on regulating the hormone melatonin. The sun produces vitamin D in the body and the link has been established between lack of sunlight and SAD. Like other mood disorders, those who suffer from SAD can feel as if there is no solution to feelings of hopelessness and depression. This disorder is also known as temporary depression or seasonal depression. Sufferers of SAD experience disabling depression that inhibits them from functioning in their normal everyday lives. SAD tends to be more commonly diagnosed in people who live in areas of the world that experience long winters months with little to no sunlight.

There are several beneficial treatments that can treat SAD effectively. Treatments can include supplements such as melatonin, cognitive behavioral therapy, light therapy, and on rare occasion, medication. The most common and widely used is light therapy. This is a therapy that should change the circadian rhythm and suppress the body’s natural production of melatonin. Melatonin is responsible for making people tired when the sun goes down and is naturally produced by the pineal gland. Suppressing the production of this natural hormone is thought to increase energy levels and allows a person to feel awake and rejuvenated. Typically light therapy is administered via light boxes with a reflective backing and a plexiglass cover. A row of florescent lights are inside the box. The reflective backing illuminates the lights and expands the ability for a person to receive the maximum absorption from the light. Blue LED lights have been shown to better absorb in the body compared to other colors. Portable devices are widely used in administering light therapy, making it easier to receive therapy. The average therapy time length is 30 minutes with consistency of treatment being most important in achieving effectiveness. Light therapy is best administered approximately 7-9 hours after the body has experienced a melatonin rush in the body. For most people this means that exposure at dawn increases the effectiveness of light therapy.

Approximately 10% of the US population is affected by SAD . States with cold winter months see a higher percentage of the disorder, while the warmer states such as Florida and California see a much lower rate of the disorder. SAD is experienced worldwide with a higher percentage rate of occurrences appearing in Arctic countries where cloud coverage is high and sun light is minimal during winter months. There is a higher occurrence of a milder version of SAD called Subsyndromal Seasonal Affective Disorder. This milder version can affect up to 15% of the world population but can be effectively treated with exercise and outdoor activities. Light therapy has been measured up to 80% effective in some studies providing a full remission to many.

  • Medline Plus Information: Information on SAD and the affects, diagnosis and treatment on the disorder with helpful videos and tools.
  • Symptoms and Diagnosis of SAD: Explores the many symptoms that identify the disorder and the diagnosis that can lead to treatment options.
  • Seasonal Affective Disorder: Helpful resource for veterans who experience the seasonal mood changes that can occur during the winter or summer months.
  • Characteristics of SAD: Outlines the characteristics and symptoms of seasonal affective disorder as well as the different types of the disorder.
  • Light Therapy for SAD: A helpful resource that outlines and provides a visual display of how light therapy can treat SAD.
  • American Family Physician: Efficacy of Therapies for SAD with case studies and epidemiology.