What is Seasonal Affective Disorder (SAD)? Everyone gets the "winter blues" - what's so different about SAD?

Many people complain of feeling down, having less energy, puffing on a few pounds, and having difficulty getting up in the morning throughout the dark, short days of winter. People suffering from SAD experience these and other symptoms to such a degree that they feel unable to function normally. They often feel chronically depressed and fatigued, and want to withdraw from the world and to avoid social contacts. They may increase their sleep by as much as four hours or more per day, have greatly increased appetite - sometimes accompanied by irresistible cravings for sweet and starchy foods, and gain a substantial amount of weight. Women frequently report worsening of premenstrual symptoms. People with SAD suffer in the extreme the kinds of changes which many others experience to a much lesser degree in wintertime.

An individual SAD sufferer, however, need not show all the symptoms described above. Sleep duration, for example, may be normal while carbohydrate craving may be extreme - or vise versa. Sometimes a symptom in the cluster is actually opposite the norm, such as insomnia as opposed to excessive sleep. A diagnosis of SAD requires a professional evaluation by a psychiatrist or psychologist. We caution against attempting self-diagnosis, it is easy to misinterpret symptoms or incorrectly rate their severity.

Recent studies indicate that about three times as many people suffer from "winter doldrums", a sub-clinical level of SAD, as suffer at a level of clinical severity. These people notice the return of SAD-like symptoms each winter and are bothered by them, but remain fully functional. As much as 25 percent of the population from the middle latitudes of the USA to Northern Canada experience "winter doldrums".

What is light therapy for winter symptoms, and how is it delivered?

Light therapy involves exposure to intense light under specified conditions. For those individuals concerned about cataracts, it is probably best to avoid UV light exposure, which is often contained to some extent in full-spectrum bulbs. The recommended light therapy system consists of a set of fluorescent bulbs installed in a box with a plastic diffusing screen, and set up on a table or desk top at which one can sit comfortably for the treatment session. Treatment consists simply of sitting close to the light box, with the lights on and eyes open. Looking at the lights is not necessary or recommended; rather, one is free to engage in such activities as reading and writing, or eating meals. What is important is to orient the head and body toward the lights, concentrating on activities on the surfaces illuminated by the lights, and not on the lights themselves. Treatment sessions can last from 15 minutes to 3 hours, once or twice a day, depending on individual needs and equipment used. Intensity and timing of treatments interact in determining the precise dosage required.

HEALTH LIGHT INC. has developed and had tested at the Clarke Institute of Psychiatry a new device (LIGHT CAP) which uses RED lights.

Early research used special "full-spectrum" bulbs producing light similar in colour composition to outdoor daylight, but more recent efforts have used ordinary fluorescent bulbs with similar results. What appears to be critical is that the level of light produced match that of light outdoors shortly after sunrise or before sunset. Light intensity is critical for adequate therapy. Systems deliver varying amounts of light which should be specified in detail by the manufacturer, with information provided as to how far away the patient should sit. The time of day of light therapy is another important factor. Many people with winter depression respond best to treatment first thing upon awakening. Some, however, do better with evening light. It is most appropriate to determine the best time of day for each individual.

Is increased exposure to normal room light therapeutic, without the use of special apparatus?

Some very light-sensitive people, living and working in dim environments, may feel improvement with increased exposure to normal room light. Research studies show, however, that most sufferers of SAD and winter doldrums require exposure to much higher light levels. Such therapeutic levels are usually at least five times higher (as measured in lux or foot-candles by a light meter) than provided by ordinary indoor lamps and ceiling fixtures in the home or office.

If outdoor light intensities are what's critical, can the therapeutic effect be achieved by spending more time outdoors in winter?

For many, however, it appears that the strongest therapeutic effect requires exposure to artificial bright light in early morning; at an hour (6:30 AM for example) when it is still quite dark outdoors during long winter nights. However, those individuals who can sleep later on winter mornings can benefit by outdoor light exposure preferably to begin as soon as possible upon awakening. These individuals should be reminded that just going outside is adequate. Looking directly at the sun is not recommended, as it could cause eye damage.

Do the lights really work?

Researchers at medical centers and clinics in the USA, CANADA and abroad have had much success with light therapy in many hundreds of patients with clear histories of SAD for at least several years. Marked improvement is usually observed within four or five days, if not sooner, and symptoms usually return in about the same amount of time when the lights are withdrawn. Most users therefore maintain a consistent daily schedule beginning, as needed, in fall or winter and usually continuing until spring, when outdoor light becomes sufficient to maintain good mood and high energy. Some people can skip treatments for one to three days, occasionally longer, without ill effect, but most start to slump quickly when treatment is interrupted.

How do the lights work?

The therapeutic level of illumination has several known physiological effects, though its mechanism of effect is still unclear. Blood levels of the light sensitive hormone melatonin, which may be abnormally high at certain times of day, are rapidly reduced by light exposure. Depending on when bright light is presented, the body's internal clock - which controls daily rhythms of body temperature, hormone secretions, and sleep patterns - shifts ahead or is delayed when stimulated by light. These physiological time shifts may be the basis of the therapeutic response. Light may also amplify the day-night difference in these rhythms. Research into the possible mechanisms is currently underway, and the final answer is not yet in.

Are there any side effects?

Side effects have been minimal. People occasionally report eye irritation and redness which can be alleviated by sitting farther from the lights or for short periods. Using a humidifier to counteract the dryness of winter air indoors may also help. A few people have reported feeling mildly nauseous when beginning light treatment; this tends to pass quickly as one accommodates to the high intensity. The most dramatic side effect, and one which occurs infrequently, is a switch from the lethargic state to an over-active state in which one may have difficulty getting a normal amount of sleep, becomes restless -- even reckless - and be unable to slow down, feel irritable, or subjectively speedy and "too high". People who have previously experienced these states in late spring or summer are particularly vulnerable. In such cases, the guidance of a clinician skilled in the use of light therapy is important.

Do the lights cause tanning?

Not usually. Most light therapy systems shield out the ultraviolet that causes tanning, or substantially reduce it. Occasionally a person with very sensitive skin shows reddening under full-spectrum lights, in which case complete UV-blocking, with filters, alternate bulbs, or a sun screen lotion is needed. This should not influence effectiveness, however, the action of light therapy is through the eyes, not the skin, and in adults UV does not reach the retina, (artificial lens implants may provide an exception).

Can the lights be combined with antidepressant medication?

Patients who have received partial benefit from antidepressants often begin light therapy without changing drug dose. If there is quick improvement, it is then sometimes possible to withdraw the drugs under clinical supervision, while maintaining improved mood and energy. Some patients find a combination of light and drug treatment to be most effective. Some antidepressant drugs, however, are known or suspected to be "photosensitizers", i.e., they may interact with the effect of light in the retina of the eyes. Users of antidepressant drugs should therefore check with their psychopharmacologist or ophthalmologist before commencing light treatment.

When are the lights contraindicated?

No adverse effects of light therapy have been found in ophthalmological examinations of SAD patients after treatment, but caution is warranted in cases of pre-existing eye disease. There are several conditions of retinal pathology (for example, retinopathy or detachment) under which bright light exposure would not be recommended. Given other eye conditions (for example, glaucoma, cataracts), or conditions under which the retina may be vulnerable (such as predisposing factors of diabetes), it is recommended that light therapy be done only with ophthalmological monitoring. Certain medications may increase the eyes sensitivity to light, and patients using them should also be followed by an ophthalmologist.

How did this treatment develop? How long has it been in use?

The first demonstration of clinical effect was in the early 1980's. Soon after, several research centers initiated clinical trials, and more than 600 SAD patients (including several hundred in Canada) have been studied to date. The method has also been used in private practices, in most cases by psychiatrists, but also by family doctors and psychologists. The number of clinicians offering light therapy is increasing dramatically year by year, though compared to drug treatments or psychotherapy, the method is not yet in widespread use.

Are the lights medically approved? Is a prescription needed? Does insurance cover their cost?

Both the American Psychiatric Association and The Society for Light Treatment and Biological Rhythms have published guidelines for use of light treatment for winter depression. The apparatus is not a prescription item, and the Food and Drug Administration has not ruled on its use. Some light boxes are available "over-the-counter," but anyone suffering serious depression should seek a doctor's recommendation before obtaining a unit, and use it under the doctor's supervision. Some people have been successful in obtaining insurance reimbursement for purchase of light therapy apparatus, based on their physicians statement that the lights are medically indicated and effective for the individuals. Provincial medical systems (OHIP etc.) do not yet cover this expense. If the policy covers drugs or psychotherapy, it is very likely that it will reimburse for light treatment apparatus.

How much do the lights cost? Can individuals build them for personal use?

Light therapy apparatus is available from several manufacturers at prices ranging from $300 to $550 (US funds) depending on configuration or the components and special features plus import duties, GST and Provincial sales taxes and shipping charges. Home construction of the apparatus is not recommended. Output must be specifically calibrated, Ultra Violet removed etc. for the safe and proper therapeutic effect. A danger of creating electrical or heat hazard also exists. The apparatus on the market should have been carefully evaluated for output intensity, compatibility of components, visual comfort, maximum transmittance with minimal beat build-up -- and, importantly, clinical efficacy in controlled research studies. These factors should be checked before purchasing any light system. Patients are urged to seek the advice of an experienced clinician regarding the use of bright fight for treatntent purposes.

Is free treatment available?

Free treatment is available for research volunteers at SAD clinical research centers in the United States, Canada and abroad. Recruitment for the winter season often begins in late summer or early fall. If you are seeking to participate in such a study in your area please check with your doctor for possible studies being done.

What other treatments are available for SAD?

Apart from moving to or taking long vacations in a climate with more available light, some sufferers find that standard antidepressant medications provide relief, even if they do not reach their normal level of well-being until spring or summer. Many patients have been in psychotherapy and have found it to be helpful to them in many ways, including coping with SAD - but, unfortunately, not in relieving the SAD symptoms.

Where is Light treatment available?

HEALTH LIGHT INC. has supplied light therapy units to the following:

Clarke Institute of Psychiatry............250 College St., Toronto, ON
Hamilton Psychiatric Hospital.............................Hamilton, ON
St. Joseph's Hospital.....................................Hamilton, ON
McMaster University Medical...............................Hamilton, ON
Hamilton General Hospital.................................Hamilton, ON
Univ. of B. Columbia, Dept. of Psychiatry.................Vancouver,BC
Smith Clinic.............................4825-51st. St., Camrose, Alta
Memorial Univ. of Newfoundland..........................St. John's, NF
Brandon Mental Health Centre..............................Brandon, Man
Royal Univ. Hospital...................................Saskatoon, Sask
Maple Ridge Hospital...................................Maple Ridge, BC
Boston Univ. School of Medicine.........................Boston, MA USA
Eden Mental Health Centre.................................Winkler, Man
Credit Valley Hospital.................................Mississauga, ON
Community Mental Health Clinic..............................Guelph, ON
Stevenson Memorial Hospital...............................Alliston, ON
London Psychiatric Hospital.................................London, ON
North Halton Mental Health Clinic...........................Milton, ON
Duke Univ. Medical Center..........................North Carolina, USA
Hop. du Saint-Sacrement.....................................Quebec, PQ
Temple University................................Philadelphia, PA. USA
Allen Memorial............................................Montreal, PQ
St. Thomas Psychiatric Hospital.........................St. Thomas, ON
Ottawa General Hospital.....................................Ottawa, ON
Toronto General Hospital...................................Toronto, ON
Flinders University.............................Adelaide, S. Australia
Universitiit-Nervenklinik................................Bonn, Germany
Kohka Sangyo..............................................Tokyo, Japan
Technion Research & Development..........................Haifa, Israel

In addition, HEALTH LIGHT INC. has supplied Light Therapy Equipment to many Doctors across Canada and USA for use in their practices.

For further information, contact:

HEALTH LIGHT INC.
P.O. Box 3899, Station C
Hamilton, Ontario
L8H 7P2

Phone 905 545-4997 *** Fax 905 545-8963
1-800-265-6020 Canada & USA