A reader asks:

 I believe I have SAD as I know my body and mind respond favorably during summer months and I get depressed when we lose daylight hours. I have also always been prone to depression, worse in winter months. Obviously SAD is proof positive of a circadian rhythm disturbance. Because I’ve always been a “night owl,”, I’ve investigated sleep disorders and found out about delayed sleep phase syndrome (DSPS). My “body clock” can literally make me turn night and day around if left to my own devices. I was told by my mother that even as a baby she had a hard time getting me to sleep and I’ve always been unnaturally tired in the morning even with a full 8 hours sleep. My question is, would light therapy be useful in my case?

Answer:

Glad you’re gaining this insight. Delayed sleep phase, difficulty awakening, and depressed mood often come in a “package”, whether seasonally or non-seasonally. Light therapy has been designed and tested for this indication, and we urge you to try it. We can’t be sure from your description, but it sounds like successful treatment may require clinical supervision with dosing adjustment of the light (intensity, exposure duration and time of administration), possibly in combination with other chronotherapy procedures. Thanks for writing.