A reader asks:

 I have just been diagnosed with delayed sleep phase. My body clock tries to make me sleep from 2 a.m. until 10 a.m., but I must wake up for work at 5:30 a.m. The doctor prescribed Ambien, but after trying it, I still have great difficulty waking up, even after eight hours of sleep, and am very groggy all morning. My doctor and I discussed light therapy but he didn’t seem to feel I needed it since my delay was not severe. I wonder if the medicine is making me fall asleep on time, but my body is still producing melatonin at the wrong time. Could this be the problem and could light therapy help? I am a teacher and in the summer when I’m not working, I sleep until 9 or 10 a.m. and then spend time outside. I don’t have a sleep problem then.

Answer:

Very well expressed, but you are presenting a complex of issues. Mostly importantly, your doctor is wrong: light therapy provides a very effective solution to mild sleep phase delay. Beyond that, your delay is about three hours, which we would consider quite serious. A major complication involves your workday rise time at 5:30 a.m., however. If you were to take light treatment at such an early hour, it would act to exacerbate your delayed sleep phase. To move your body clock earlier, the light therapy strategy requires using lights near the end of your “internal night,” most likely after 8 a.m. when you are already out of the house. You could get a grip on this problem in late summer or on winter vacation. After a few days of light at 8 a.m., you would begin to step up the light progressively earlier in order to advance your body clock. You might also make headway by using low dose slow-release melatonin at about 10 p.m., whether or not in conjunction with light, and then moving the dose progressively earlier. Because of the complexity of your situation, we urge proceeding under expert clinical guidance. For relevant background, see the Termans’ chapter in Principles and Practice of Sleep Medicine, downloadable free at www.cet.org. And perhaps share it with your doctor!