Seasonal Affective Disorder (SAD)

To Your Health-- CHRC Newsletter, Volume 3(3), Fall 1998

Fall 1998

By Gale Hylton, MD, PAMF Psychiatry

Seasonal Affective Disorder (SAD) is a phrase that is frequently talked about in winter. It is a disorder connected with a decrease in daylight. Four percent of the population suffers from SAD, yet most people don't know exactly what it is.

Definition

Seasonal Affective Disorder is a special category of major depression and bipolar disorder. Briefly, according to the Diagnostic and Statistical Manual IV of the American Psychiatric Association, SAD is defined as the presence of five of the following symptoms for at least two weeks:

  • Depressed mood.
  • Diminished interest or pleasure in most activities.
  • Significant unintended weight loss or gain.
  • Insomnia or excessive sleeping.
  • Restlessness or slowed activity.
  • Fatigue.
  • Feelings of worthlessness or excessive guilt.
  • Indecisiveness and decreased concentration.
  • Recurring thoughts of death: suicidal thoughts or attempts.

Bipolar disorder occurs when the major depression is interspersed with episodes of high energy, euphoria, irritability and impulsiveness.

There are four criteria for the seasonal pattern of depression. These criteria include: a correlation between the onset of major depressive episodes and the time of year, with full remissions occurring at the same time each year; two depressive episodes demonstrating the seasonal connection; and seasonal episodes of depression outnumbering non-seasonal ones. For example, an individual finds that for three years in succession she gets very fatigued, overeats, sleeps 12 hours per day and loses interest in most activities every November, with a return to her normal function in March.

Clinical Aspects

Seasonal depressions most commonly occur in winter and are associated with the decrease in daylight. Many individuals who suffer from seasonal depression describe themselves as "human bears" -- they hibernate. Sleeping excessively, overeating, social withdrawal, fatigue, decreased libido, irritability and craving carbohydrates are common symptoms. Low motivation and cognitive difficulties are frequently present. Depressed mood often occurs following the onset of fatigue, increased sleep and appetite. Summers are remembered as times of high energy with the individual being more outgoing and needing less sleep, or just feeling motivated and interested in life. Winter is dreaded, and warm sunshine longed for, since it brings hope and power. I have noticed many of my patients with depression, although not clinically diagnosed with SAD, experience worsening of their symptoms during the winter, especially during prolonged gray, rainy periods. Symptoms of their depressive illness are worsened by decreased daylight.

SAD differs from winter blues in severity. Individuals with SAD are markedly less productive, seriously withdrawn, lose interest in pleasurable things and have conspicuous changes in energy, sleep and/or weight. Significant depression lasts more than two weeks in winter. These individuals frequently will have consulted with a physician or therapist regarding seasonal change. Those with winter blues experience much milder changes and have minimal difficulties in functioning, even though they may notice seasonal decreases in mood and energy. Winter blues can be a harbinger of future SAD. For example, someone with winter blues who moves from a sunny winter climate to the northern latitudes with less daylight and more gray days may develop a true seasonal depressive disorder.

Affected Population

Women seem to be more vulnerable to SAD, with the ratio of incidence averaging three to four women of reproductive years to one man. The childbearing years are important in that they dovetail with the peak age of onset, which is between 20 and 40. One study has shown the average first episode occurring at age 23, while another shows the age for first occurrence at 32.

Four percent of the population suffers from SAD, and 10-13% has sub-clinical symptoms. A significant number of individuals (50-60%) has seasonal changes in weight, mood and energy, but these variations are not disruptive to functioning.

Causes of SAD

There seem to be three factors in the development of this form of depression. A biologic vulnerability based on family history and, as noted above, gender. Most people with SAD have one close relative with depression. Twin studies show a clear genetic correlation. Light deprivation is another predisposing factor. Stress frequently triggers initial and subsequent episodes, and it may cause the transition from winter blues to SAD. Additionally, research shows that patients have a decrease in levels of serotonin (a neurotransmitter involved in depression) in October as well as a disruption in circadian rhythms.

Diagnosis and Treatment

Diagnosis of SAD is essential. Individuals should seek medical assistance if any or all of the following are present:

  • Decrease in concentration.
  • Inability to complete tasks.
  • Decreased attendance and performance at work.
  • Previously outlined symptoms of depression (see definition).

Your primary care physician, a psychiatrist or a therapist who is knowledgeable about depression and its seasonal variations, can provide medical assistance.

Once a diagnosis of SAD is made, there are several treatment options:

1. Phototherapy

This is the treatment of choice. It is provided by a specially designed light box with fluorescent bulbs that do not have harmful ultraviolet rays. The bulbs are much brighter than typical indoor illumination. Phototherapy is comparable to the light received on a clear day a half-hour after sunrise. Optimal phototherapy provides 10,000 lux for up to 30 minutes per day. Older light boxes of 2,500 lux require longer treatments of up to two hours. Phototherapy, which must be prescribed by a psychiatrist, is most successful if started at the onset of symptoms. Treatment is usually conducted in the morning and may be initiated by a device that simulates the day's first light, known as a dawn simulator. Phototherapy works via the eyes. Light boxes can be obtained from a number of companies that specialize in phototherapy devices. Prices for light boxes range from $300 to $600. Some insurance companies cover light boxes but will require a written prescription and may request clear documentation of a seasonal form of depression. Response to light therapy typically occurs in two to four days. Side effects can include agitation, irritability, eyestrain and dry skin.

2. Medication

The most commonly used pharmacological treatments for SAD are the selective serotonin re-uptake inhibitors (SSRIs), which include drugs like Prozac, Paxil, Zoloft and Cylexa. Tricyclic antidepressants, monoamine oxidase inhibitors, Wellbutrin and Lithium have also been used successfully, but generally patients experience more side effects. For some individuals medications are necessary year-round, and for others they may be used from fall to spring. Dosage and duration of use are based on individual history, the degree of response to other therapies and severity of symptoms.

3. Psychotherapy

Psychotherapy is usually used concurrently with other forms of treatment. The patient and mental health provider set goals for therapy and determine duration based on individual needs.

Forms of talk therapy which can be helpful include: cognitive treatment, which helps individuals with negative thinking; behavioral therapy, which may focus on maladaptive patterns (such as not paying bills when feeling depressed); and insight-oriented treatment. The latter is a long-term approach that focuses on resolving psychological conflicts and can be extremely helpful to those with SAD or any form of depression. Family and couples therapy may be used at times because of the impact of SAD on people close to the patient. Education and support are important components of all the psychotherapies.

What a Person with SAD Can Do

Persons with SAD need to perform a fall check-up, which should include evaluation of stress levels and how they can be minimized, and try to spend time outdoors to get natural light. Exercise, especially outside, can help alleviate symptoms. Consideration should be given to diet. Although research is inconclusive, decreasing carbohydrate intake and increasing protein seem to be helpful to some patients with weight gain and cravings. Early fall is the appropriate time to schedule a follow-up appointment with a psychiatrist to review goals, determine when to start dawn simulator, phototherapy or medications. Additionally, individuals may benefit tremendously from taking a winter vacation to a sunny locale.

Summary

Help is available for all forms of depression, including SAD. If you suffer from seasonal mood changes, other forms of depression or have questions about these conditions, see your primary care provider, psychiatrist or a knowledgeable therapist.

If you have been diagnosed with SAD, now is the time to reduce stress, see your psychiatrist to plan for the fall, increase your exercise and plan a winter vacation to a sunny St. Somewhere.

References

Diagnostic and Statistical Manual of Psychiatry, American Psychiatric Association Press, 1994.

Resenthal, Norman, Winter Blues, Guilford Press, 1993.

Rosenthal, Norman, Seasonal Affective Disorders, Lecture at Psychopharmacology in Practice, Wash. DC, 1994.

Hales, Yudofsky, and Talbott, Textbook of Psychiatry, 2nd Edition, American Psychiatric Press, 1994.