Seasonal Affective Disorder (SAD)

Medically Reviewed on 1/2/2024

What is seasonal affective disorder?

Seasonal affective disorder (SAD), formally referred to as recurrent depression with seasonal pattern, is a type of depression that tends to occur (and recur) as the days grow shorter in the fall and winter.
Seasonal affective disorder (SAD), formally referred to as recurrent depression with seasonal pattern, is a type of depression that tends to occur (and recur) as the days grow shorter in the fall and winter.

Seasonal affective disorder (SAD), formally referred to as recurrent depression with seasonal pattern, is a type of depression that tends to occur (and recur) as the days grow shorter in the fall and winter. It is believed that affected people react adversely to the decreasing amounts of sunlight and the colder temperatures as the fall and winter progress. It is important to note that although seasonal affective disorder usually presents in the fall and winter there are those who suffer from this condition during the summer instead of, or in addition to, during the fall or winter.

The seasonal affective disorder has not been long recognized as an official diagnosis. The term first appeared in print in 1985. The seasonal affective disorder is also sometimes colloquially called winter depression, winter blues, or the hibernation reaction.

The incidence of seasonal affective disorder increases in people who are living farther away from the equator. Statistics on the seasonal affective disorder in the United States include that this disorder occurs in 1% to 10% of adults and is dependent on geographical location. Seasonal affective disorder is about four times more common in women than men, and the average age of people when they first develop this illness is 23 years of age. People of all ages can develop seasonal affective disorder.

What are the symptoms of seasonal affective disorder?

Although there is no specific diagnostic test for the illness, it is understood that since it is a form of depression, the symptoms of the condition include tiredness, fatigue, sadness or a sense of general discontent, crying spells, irritability, apathy, trouble concentrating, body aches, loss of sex drive, poor sleep, decreased activity level, and appetite changes, particularly overeating, especially of carbohydrates and weight gain. When the condition occurs during the summer, the symptoms are more commonly insomnia, poor appetite, and weight loss, in addition to anxiety, irritability, difficulty concentrating, and crying spells. Social isolation, with the potential resulting loneliness, also occurs at times with summer seasonal affective disorder. If the condition is severe, it can be associated with thoughts of suicide.

The symptoms of seasonal affective disorder typically tend to begin in the fall each year, lasting until spring. The symptoms are more intense during the darkest months. Therefore, the more common months for the condition to occur will vary depending on how far away from the equator one lives.

What are causes and risk factors for seasonal affective disorder?

Seasonal affective disorder seems in many cases to develop from inadequate exposure to bright light during the winter months. Studies show that bright light changes the chemicals in the brain. Exactly how this occurs and the details of its effects are being studied. Factors like high levels of melatonin and low levels of serotonin in the brain, as well as low levels of vitamin D levels in the blood, are found to be associated with a higher occurrence of seasonal affective disorder and some other depressive conditions.

SLIDESHOW

Learn to Spot Depression: Symptoms, Warning Signs, Medication See Slideshow

What is the treatment for seasonal affective disorder?

In addition to being key in the prevention of seasonal affective disorder, regular exposure to light that is bright, particularly fluorescent lights, significantly improves depression in people with this disorder when it presents during the fall and winter. The light treatment is used daily in the morning and evening for best results. Temporarily changing locations to a climate that is characterized by bright light (such as the Caribbean) can also be effective. Light treatment has also been called phototherapy. Individuals who suffer from the seasonal affective disorder will also likely benefit from increased social support during vulnerable times of the year.

Phototherapy is available in the form of lightboxes, used for approximately 30 minutes daily. The light required must be of sufficient brightness, approximately 25 times as bright as a normal living room light. The light does not need to be actual sunlight. It seems that it is quantity, not necessarily quality of light that matters in the phototherapy of seasonal affective disorder. The most common possible side effects associated with phototherapy include irritability, insomnia, headaches, and eyestrain.

Antidepressant medications, particularly those from the selective serotonin reuptake inhibitor (SSRI) group of medications, have been found to be effective in treating a seasonal affective disorder that occurs during summer as well as that which tends to occur during the fall or winter. Examples of SSRIs include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), escitalopram (Lexapro), and vortioxetine (Trintellix). Common side effects for this class of medications include insomnia, nausea, diarrhea, and many can cause decreased sex drive or performance. As with any other mood disorder, psychotherapy tends to accentuate the effectiveness of medical treatment and therefore should be included in the approach to addressing this disorder. In individuals who are perhaps vulnerable to the development of the bipolar disorder, either light therapy or antidepressants can cause a manic episode as a side effect.

Since stimulant medications like modafinil (Provigil) may be a helpful addition to other treatments for seasonal affective disorder, other stimulants like methylphenidate (Ritalin) may play a future role in addressing this disorder. Acupuncture may be a viable alternative intervention to antidepressant medications, particularly in pregnant women, for whom medications should be used with particular caution.

Determined to be equally effective as phototherapy or antidepressant medication in addressing seasonal affective disorder, cognitive behavioral therapy (CBT) is another viable option for treating this illness. This form of psychotherapy involves the therapist working with the client to help the depression sufferer identify and understand ways of thinking that may be obstacles to improving their mood, thereby increasing the ability of the person with the seasonal affective disorder to alleviate symptoms.

Chronotherapy, which uses environmental input to affect biorhythms, is thought to be a helpful aspect of treatment for seasonal affective disorders, as well as for other kinds of depression. This treatment uses methods like controlled sleep deprivation to affect the seasonal affective disorder sufferer's brain chemicals in a positive way.

Lifestyle changes that can help decrease the symptoms of seasonal affective disorder include increasing time spent outdoors, more physical exercise, and maintaining eating habits that are high in lean proteins, fruits, vegetables, and complex carbohydrates while decreasing the intake of refined sugars and other carbohydrates. Remedies that do not necessarily require the involvement of healthcare professionals, or so-called home remedies, include vitamin D supplementation and taking melatonin in the evenings.

What is the prognosis and potential complications of seasonal affective disorder?

People who receive treatment for seasonal affective disorder in a timely way tend to recover well. However, as with other forms of major depression, seasonal affective disorder is a risk factor for developing a number of other mental-health symptoms and disorders, engaging in self-mutilating behaviors, or taking one's own life. People who suffer from this illness are also more vulnerable to having troubled relationships, low performance at school or work, and developing some medical and substance use disorders.

Is it possible to prevent seasonal affective disorder?

Attempts to prevent future episodes of seasonal affective disorder using psychotherapy or light therapy have inconsistent results, but preventive medication treatment is thought to have promise. Therefore, health-care professionals tend to focus on lifestyle changes that can be helpful, as well as recommending preventive treatments based on what was most helpful for the individual sufferer in the past.

Where can people get more information about and support for seasonal affective disorder?

American Association of Suicidology
http://www.suicidology.org
202-237-2280

American Foundation for Suicide Prevention
http://www.afsp.org

Jason Foundation
http://www.jasonfoundation.com

National Alliance for the Mentally Ill
2101 Wilson Boulevard Suite 302
Arlington, VA 22201

Seasonal Affective Disorder Support Group
http://www.seasonalaffectivedisordersupportgroups.com

Medically Reviewed on 1/2/2024
References
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Arlington, Virginia: American Psychiatric Association, 2013.

"Seasonal Depression." Mental Health America (MHA). <http://www.nmha.org/go/sad>.

NIMH. "Seasonal Affective Disorder." <https://www.nimh.nih.gov/health/publications/seasonal-affective-disorder>.