A reader asks:

 I’ve noticed that light therapy boxes (LTB’s) have uses for SAD, but I have heard that they can be effective with insomnia. How do you use LTB’s on someone with early, middle or late insomnia — especially late insomnia to stop my brother from waking at 4 a.m. every morning. He doesn’t want to use medications.


You are correct that light therapy can alleviate certain forms of insomnia, when the root cause is misalignment of internal circadian rhythms with the day-night cycle. Waking up at 4 a.m. could be due to several other factors, however, in which case light therapy would be ineffective. Diagnosis and treatment supervision by a sleep specialist is advised. A recent medical handbook chapter on the topic, which you might recommend to your doctor, is: Terman M, Terman JS. (2000) “Light therapy,” in Principles and Practice of Sleep Medicine, third edition by Kryger M., Roth T., Dement W., Editors, Philadelphia, W.B. Saunders, pp. 1258-1274.