Seasonal Affective Disorder

Seasonal affective disorder (SAD) is a type of depression. It is associated with the seasonal changes in light. SAD most commonly occurs in late fall and lasts through the winter and into spring. SAD is more than feeling down, it interferes with normal daily functions during these times.

  • Causes

    The causes of SAD are not completely clear. Some factors that may play a role include:

    • Reduced sunlight—This affects internal clocks, readjusting hormones and brain chemicals.
    • Increase in melatonin production—Melatonin may cause symptoms of depression. This hormone is produced in higher amounts in the dark.
    • Low serotonin—Serotonin is a brain chemical that is associated with well-being. In people with SAD, there may be a lack of serotonin in the brain.

  • Definition


    Seasonal affective disorder (SAD) is a type of
    depression.
    It is associated with the seasonal changes in light. SAD most commonly occurs in late fall and lasts through the winter and into spring. SAD is more than feeling down, it interferes with normal daily functions during these times.

    Brain—Psychological Organ
    Brain face skull
    SAD may be caused by fluctuations in hormones and brain chemicals.
    Copyright © Nucleus Medical Media, Inc.

  • Diagnosis

    The doctor will ask about your symptoms and medical history. A physical and psychological exam will be done.

    A diagnosis of SAD will only be made if you have some of the symptoms above and:

    • Your symptoms have occurred annually for at least two years
    • No nonseasonal major depressive episodes have occurred during same period
    • You have complete relief from symptoms during the summer months

  • Prevention

    If you have SAD each year, your doctor may make suggestions to help prevent the symptoms from coming. For example, certain antidepressants or light therapy may be used to prevent SAD symptoms from coming if started before autumn.

  • Risk Factors

    SAD is more common in women than in men, often appearing in young adulthood. People who live in northern latitudes also have an increased risk of developing SAD.

  • Symptoms

    Symptoms appear and peak during the winter months. As spring and summer approach, symptoms disappear. Symptoms may include:

    • Depressed mood, feelings of sadness
    • Fatigue/lack of energy
    • Irritability

    • Oversleeping or
      insomnia
    • Social withdrawal
    • Difficulty concentrating
    • Decreased sexual desire
    • Overeating
    • Weight gain
    • Cravings for sweet or starchy foods

  • Treatment