Ask The Doctor Forum

CET joins the Center for Light Treatment and Biological Rhythms at Columbia University Medical Center, New York City to bring you Ask the Doctor – a free question-answer forum with clinical and research specialists. First, check our extensive list of past questions and answers using the keyword search feature to the left. Then, ask your question if it has not already been addressed.

Our specialists will choose items of general interest to CET’s visitors. Although we try to respond promptly, sometimes there is a delay as we review and assign questions – so check back frequently for updates. For ethical reasons, we do not respond to personal inquiries about clinical status or treatment. You should not identify yourself by name or email address in this forum.


If you learn something from Ask the Doctor, or have suggestions for developing this website feature, please write us at If you want to join CET’s email list, write us at

Columbia University Medical Center