A reader asks:

My goals are to regularize my sleep-wake cycle and treat some mild but persistent depression. At your suggestion, I took your Automated Morningness-Eveningness Questionnaire (AutoMEQ). It indicates that my natural bedtime is at approximately 12:15 a.m. and it recommends that I begin light therapy at 7:00 a.m. This would allow for 6 3/4 hours of sleep, which almost always feels like too little sleep for me–I usually need about 8 to 8 1/2 hours of sleep to function reasonably well. Bearing all of this in mind, could I go to sleep sooner than 12:15 a.m. if I feel sleepy? Or should I try to stick to the 12:15 a.m. to 7:00 a.m. schedule proposed in the AutoMEQ?


We give two perspectives in our answer:

  1. Some people with depression sleep significantly longer than when they are feeling well. Therefore, if you respond to light therapy at 7:00 a.m., you may find that 6 3/4 hours of sleep is surprisingly refreshing and adequate.
  2. Because the light therapy schedule is designed to shift your internal circadian clock earlier, it is quite possible that you will begin to get sleepy before 12:15 a.m. Go to sleep when that feeling sets in–don’t force yourself up until 12:15 a.m. You may thereby partially or even totally compensate for any sleep loss during light treatment.

The AutoMEQ does not assign bedtime, it just tells you when your circadian clock is ready to initiate sleep BEFORE you start light therapy. Follow your nose, and you will find the best bedtime after treatment at 7:00 a.m. begins