Seasonal Depression (SAD)

Seasonal Depression Overview

Seasonal affective disorder (SAD) is a type of depression that is tied to seasons of the year. Most people with SAD are depressed only during the late fall and winter (sometimes called the "winter blues") and not during the spring or summer. A small number, however, are depressed only during the late spring and summer.

SAD is most common in young adult women, although it can affect men or women of any age. In North America, SAD may affect as many as 6 of every 100 people, more in the Northern portions of the country than in the South. Another 10-20% of people may have a milder form of seasonal mood change.

Like all types of depression, SAD can have a devastating effect on a person’s life. Fortunately, almost all people with SAD can be helped with available therapies.

Seasonal Depression Causes

The exact causes of seasonal affective disorder (SAD) are unknown.

• Chemical changes in the brain caused by changes in the amount of sunlight are probably involved. People who live in geographical locations that are dark or cloudy during the winter are most likely to have SAD.

• A tendency to have SAD may run in some families.

Seasonal Depression Symptoms

Seasonal affective disorder (SAD) may have some of the same symptoms as other types of depression.

• Most people have only some of these symptoms, not all.
  
  
  • Depressed mood
  
  
  • Loss of interest in usually enjoyable activities
  
  
  • Fatigue or loss of energy
  
  
  • Feelings of worthlessness or hopelessness
  
  
  • Poor concentration, indecisiveness
  
  
  • Recurrent thoughts of death or suicide
    
• The symptoms of SAD come back every year, and for any specific person, they tend to come and go at about the same time each year.


• Winter SAD
  
  
  • Sleeping more than usual
  
  
  • Craving for sugar, starchy foods, or alcohol
  
  
  • Weight gain
  
  
  • Irritability
  
  
  • Conflicts with other people
  
  
  
  • Heaviness of arms and legs
  
  
  • Behavior disturbances (in children)
    
• People with winter SAD may seek out light places or sunlight, or like to have lots of artificial lights on.


• Summer SAD
  
• Insomnia


• Poor appetite


• Weight loss


• Agitation


• Anxiety

When to Seek Medical Care

Seek medical care if you think you have seasonal affective disorder or another type of depression, or if any of the following occur:

• Feelings of extreme sadness, hopelessness, or emptiness


• Inability to get out of bed or carry on normal activities


• Persistent loss of energy or increased need for sleep


• Unexplained change in appetite for food


• Changes in behavior that cause problems with family, friends, or work


• Feelings of wanting to die, wanting to commit suicide, or hurting yourself

Seasonal Depression Treatment

Self-Care at Home

The following activities or lifestyle changes may help prevent seasonal affective disorder or improve the symptoms:

• Spend at least 30 minutes outside every day.


• Set a timer on a light to go on early in the morning in the bedroom.


• Use a dawn simulator for a more naturalistic artificial dawn.


• Take daily walks outside.


• Increase indoor lighting with regular lamps and fixtures.

Medical Treatment

Bright-light therapy: This is exposure to bright artificial light, brighter than usual home or office lighting. Bright-light therapy relieves symptoms for about two thirds of people with seasonal affective disorder.

• Bright-light therapy products are available for sale and range in cost from $200-500. They range from 2,500-10,000 lux. Many experts recommend that 10,000 lux be used. Only devices that filter out harmful ultraviolet waves should be used. Types of devices include light panels or boxes, blankets, and visors.


• The bright-light source should be placed at eye level. Although staring at the light source is not recommended, the light must enter the eyes if it is to work. (Simple skin exposure does not work.) An approved bright-light therapy device should not harm the eyes if used as recommended.


• About 30 minutes of exposure to 10,000 lux each day is enough to relieve symptoms in most people. Others require greater exposure, as long as 45 minutes twice a day. You may need some trial and error to find the right amount. Your health care provider will guide you.


• Properly used, bright-light therapy has few side effects. A few people have reported eyestrain, headache, fatigue, irritability, sensitivity to light, or inability to sleep (only if therapy is used late in the day).


• Certain medications make you more sensitive to light. If you are taking any of these, you cannot use light therapy. Be sure to inform your health care provider of all the medications you are taking, including nonprescription medications and dietary supplements.


• Tanning beds should not be used for bright-light therapy as they do not filter out harmful ultraviolet waves.


• You may notice improvement in symptoms within a few days, or it may take as long as 3-4 weeks after starting therapy.

Medications

Antidepressant medications are useful for people who need further treatment because their symptoms improve only slightly or not at all with bright-light therapy. Most of these people are treated with antidepressant medication. To read more about antidepressants, see Understanding Antidepressant Medications

• The medications used most frequently are the selective serotonin reuptake inhibitors, or SSRIs (for example, Prozac and Zoloft).


• These agents may take 2-4 weeks to improve symptoms.


• Unwanted side effects depend on which medication is used. Your health care provider can tell you about side effects.


• Do not stop your medication abruptly. Stop or change dose only after consulting your health care provider.