by Riley J

Seasonal Affective Disorder

(SAD)

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.

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.

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. SAD may cause:
  • 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

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 2 years
  • No nonseasonal major depressive episodes have occurred during same period
  • You have complete relief from symptoms during the summer months

Treatment

Light Therapy

Light therapy provides a special type of lighting to your body. Therapy includes sitting a few feet away from an ultra-bright light for a certain amount of time each day, usually in the morning. You will be able to read or work during the therapy, as your eyes will remain open. Treatment usually lasts about 30 minutes each day.
There is some evidence that light therapy may be as effective as antidepressant therapy, but with fewer side effects.
Tanning beds are not recommended as a source of light therapy. They give off ultraviolet light, which can increase the risk of cancer. They also have not been proven effective for treating SAD.
Many people find that getting outdoors for a walk each day is also helpful.

Antidepressant Medications

Your doctor may prescribe antidepressant medications or supplements.

Psychotherapy

Therapists can help you learn ways of managing stress and the symptoms of SAD.

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.

RESOURCES

Depression and Bipolar Support Alliance (DBSA) http://www.dbsalliance.org

National Mental Health Association http://www.mentalhealthamerica.net

CANADIAN RESOURCES

Canadian Mental Health Association http://www.cmha.ca

Canadian Psychological Association http://www.cpa.ca

References

Johansson C, Smedh C, et al. Seasonal affective disorder and serotonin-related polymorphisms. Neurobiology of Disease. 2001;8:351–357.

Seasonal affective disorder. American Academy of Family Physicians website. Available at: http://familydoctor.org/familydoctor/en/diseases-conditions/seasonal-affective-disorder.html. Updated September 2012. Accessed September 28, 2014.

Seasonal affective disorder. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated December 19, 2012. Accessed September 28, 2014.

7/20/06 DynaMed's Systematic Literature Surveillance. http://www.epnet.com/dynamed/what.php: Lam RW, Levitt AJ, et al. The Can-SAD study: a randomized controlled trial of the effectiveness of light therapy and fluoxetine in patients with winter seasonal affective disorder. Am J Psychiatry. 2006;163:805-812.

Revision Information

Health Library Search

Only show results from the selected categories.











3 Genetics and Mental Health lifestyle - mental health

Could your genes put you at a higher risk for a mental health condition? Have researchers discovered a link between certain genes and the development of schizophrenia, de...

You’ve just had a heart attack. You want to work towards recovery, so you’re focused on your heart and body. But hold on, say doctors, don’t lose sight of your mental h...

Men get depressed, as do women. But depression affects men differently from women. Why is this the case? And what does it mean for men?...

6 Can Folic Acid Help Ease Depression? lifestyle - mental health

Studies suggest that folic acid deficiency may occur in patients with severe depression, and that treatment with the vitamin may enhance recovery of the mental state. Wha...

Depression in the workplace is a serious, yet often undiscussed problem. No job category or professional level is immune to depression and even a formerly outstanding emp...

8 The Role of Depression in Adolescent Obesity lifestyle - kids' & teens' health

You remember a time when little Johnny would hurry home from school, grab an apple, and race out the door to play with his friends. Now he comes home, goes straight up t...

Been feeling down or hopeless? Do you find little pleasure in things you used to enjoy? These may be signs of depression. Many Americans are depressed, but have not been ...

20 Diagnosis of Bipolar Disorder condition indepth