A reader asks:

 I have suffered from delayed sleep phase syndrome since I was a little girl. I am now 46 and suddenly too old to live with 4 hours of sleep every weeknight. I am so exhausted that all I want to do during the weekend is sleep my natural hours, 6 a.m. to 2 p.m. Unfortunately, during the week I have to get up before 6 a.m., but even as sleep-deprived as I feel all day, by midnight I get a second wind. I rarely ever fall asleep before 2 a.m., and then I keep waking up because I am usually hungry at that time of the night. I have tried pills, melatonin, etc. I want to try light therapy. Any advice as to what kind of lamp, how long to use it for, at what time?


Word To The Wise: your present weekday schedule reinforces your “circadian sleep phase disorder,” because you are now receiving light exposure at a time of day (approximately 6 a.m. to noon) that forces the internal biological clock later, when you need it to be forced earlier. Light therapy may indeed be right for you to try at this point. It has helped many patients with this problem, by re-synchronizing the internal clock with external solar time. Whether you could do this successfully on your own is a big question, since the lighting schedule has to be continually adjusted until you meet your goal (for example, easy sleep onset at 11 p.m.).

Intensive Therapy Needed

In our experience, progress and schedule need to be monitored by a clinician who can advise “next steps” every few days for the first few weeks. Furthermore, at the start, you would need to devote some continuous vacation time to the treatment, because the lighting schedule would begin toward the end of your “subjective night,” around 1 p.m., with 30- to 60 minute exposures, and move successively earlier every few days, possibly in 30-minute steps. (Sometimes faster progress is feasible). Additionally, you would have to carefully minimize room light exposure after 11 p.m., allowing yourself only enough light to comfortably read, watch TV, and sleep in darkness.

Proper Use of Melatonin

You say that melatonin did not work for you, but that could easily be due to inappropriate scheduling. A dose of slow-release melatonin (no more than 3 mg), taken 12 hours before the scheduled light therapy, might greatly expedite the re-synchronization process.

Try Dawn Simulation

As for recommended lighting apparatus, see www.cet.org. Once you re-synchronize, you may benefit from maintenance treatment with dawn simulation (also described on that website) scheduled for about 4:30 to 6:00 a.m. None of these procedures constitute a “cure,” in the usual sense of the word; rather they are correctives that you would always need to maintain.