What is Seasonal Affective Disorder?

SAD is a type of depression that usually occurs during the fall and winter months when there is less daylight.

What are the causes of SAD?

  • The causes of SAD are not known, but genetics and age may be a factor.
  • There are a couple of theories about the causes of SAD:
    • Abnormalities in how the body manages its internal biological clock. The circadian rhythm may not be inline with the 24 hour circadian cycle.
    • The role of Melatonin, which is a hormone that helps control body temperature, hormone secretion and sleep. It is produced in a specific brain area during hours of darkness. For those with SAD, Melatonin is produced more during low-light months, which can lead to symptoms of depression.

Are there any symptoms of SAD?

  • The following are common symptoms of SAD:
    • Mood changes: increased sadness, irritability, and anxiety
    • Appetite changes: increased appetite and cravings for carbohydrates and sweets
    • Weight gain
    • Sleep and activity changes: increased sleep duration, lower quality of rest, and daytime fatigue
    • Menstrual difficulties

What treatment is available for SAD?

  • The most common treatments of SAD are light therapy, medications, and psychotherapy

What is Light Therapy?

  • Light therapy is a common treatment for SAD which consists of the person sitting in front of a light box. The light box gives off a type and intensity of light that is not found in normal household lighting. The light box also mimics outdoor light.
  • Light therapy, when used consistently, causes biochemical changes in the brain that can lift mood and relieve symptoms of SAD. It can suppress the brain's production of Melatonin to regulate the body's internal clock.

How do you use Light Therapy?

  • To increase the effectiveness of therapy, the light must enter your eyes indirectly, not directly.
  • The three key elements of light therapy are intensity, duration, and timing
    • Intensity: The light's intensity is 10000 lux
    • Duration: Duration of each session is approximately 30 minutes
    • Timing: Light therapy is most effective in the morning

What are the benefits of Light Therapy?

  • Alternative to medications, such as antidepressants
  • Supplement to psychotherapy
  • Light box requires no prescription. (Available in Counseling And Psychological Services)
  • Can use while reading, watching TV, working out, etc.
  • Can start to feel better within a few days or few weeks

Are there any drawbacks of Light Therapy?

  • Light therapy, on a rare occasion, may trigger episodes of mania in people with bipolar disorder. There have also been reports of thoughts of suicide after treatment for those with severe depression.
    • Light therapy alone may not be fully effective.
    • Light therapy is not officially approved by the FDA as treatment of SAD due to the lack of sufficient evidence.

What are the side effects of Light therapy?

  • The following are some reported side effects of Light therapy, but they are fairly uncommon.
    • Eyestrain
    • Irritability
    • Headache
    • Fatigue
    • Agitation
    • Dry Mouth
    • Nausea
    • Sleep Disruptions
    • Insomnia
  • To reduce side effects:
    • Reduce treatment time
    • Move farther away from the light box
    • Take breaks during long sessions
    • Change the time of day light therapy is used

When should someone NOT use Light Therapy?

  • Skin is sensitive to light
  • You take medications that react with sunlight
  • You have an eye condition that makes your eyes vulnerable to light damage