Insomnia
Some people have difficulty falling asleep before the early morning hours, and, not surprisingly, have difficulty awakening when most people start their day. This problem, known as "delayed sleep phase syndrome," or DSPS, has been corrected in many cases through the use of bright light therapy. By using a bright light at the end of someone's "subjective night" (which might end at midday, given late awakening), the sleep phase can be gradually shifted earlier such that one is able to achieve a normal sleep schedule. The treatment acts by its effects on the internal biological clock, bringing the clock into sync with local time. In contrast, DSPS patients often fail to respond to sleeping pills, which don't reset the brain's clock, but put people at a risk for becoming dependent on the medication.
Conversely, some people can't resist falling asleep far too early and waking well before sunrise. Light therapy at the start of their subjective night, in the evening, can coax the biological clock later, thus normalizing - or at least improving - the sleep pattern. This technique may be especially valuable for older people, who are prone to developing advanced sleep phase syndrome, or ASPS. It has even been suggested that sitting all evening in a dimly lit room predisposes people to ASPS, and even turning up normal room lights can alleviate the problem in many cases.
DSPS and ASPS are extremes on the dimension of insomnia. Many more people experience such problems at milder severity - for example, they want to go to sleep at 11:30 p.m. but just can't fall asleep till 1 a.m. As a result, it's very hard to wake up alert for a normal work day. In just a day or two, bright light therapy at the breakfast table can often do the trick.
Antepartum Depression
Perhaps one in 10 women suffer from a depressive episode during pregnancy, which is a time when medications need be strictly controlled in order to protect the fetus. Furthermore, being depressed during pregnancy increases the likelihood of a postpartum depression, so every effort should be made to avoid a depressive episode. Might lights work here? Investigators at Yale, Columbia and Case Western Reserve have said yes. They found major improvement in antepartum depression over five-week treatment trials, and several of their patients continued treatment through the postpartum period. This work continues at the University of Pittsburgh, with free home treatment and follow-up. For information about participating, email a confidential inquiry with your name, address and daytime phone number, to klw17@pitt.edu. State your stage of pregnancy (1st, 2nd, 3rd trimester) and briefly describe the depression you are experiencing, when it began, and any current treatments. You may also learn more by visiting: http://www.pregnancylight.org/.
Chronic Fatigue Syndrome
CFS is a disabling long-term condition with distinct physical as well as psychological components. Symptoms persist on and off year round, yet a recent study showed that more than one-third of CFS patients experience distinct seasonal variation, with winters worse. Among that group, oversleeping, daytime fatigue, carbohydrate craving and eating were indistinguishable from patients with SAD. Furthermore, seasonal CFS patients were significantly more likely to have experienced a depressive episode in the past year, usually in winter.
An implication is that they might respond to light therapy. Indeed, case studies at Columbia University Medical Center (New York) and University of British Columbia (Vancouver) have shown marked improvement. Patients improved mainly in the symptoms that typify SAD, but some also showed improvement in physical symptoms of CFS (such as joint pain) that are rarely seen in SAD. Clinical trials are a high priority, especially considering that there are few specific treatment interventions for CFS, and patients often receive multiple medications (including sleeping pills and antidepressants) with unclear effect. Since light therapy for CFS is still at a preliminary investigational phase, we strongly discourage self-treatment; if light is administered inappropriately, there is even a risk that symptoms could worsen. However, in our opinion, it is an option for doctors to consider, following similar treatment guidelines as for SAD.
