A reader asks:

I’ve been using light therapy for three to four weeks with great success. My problem is that every Saturday I party with friends and don’t go to bed before 2 – 3 AM. In an earlier discussion about using light treatment later than the recommended time, you say that “light therapy later in the morning is better than skipping it altogether.” I was wondering if it’d not be even better to try hard to wake up on time for my session (7:15 AM, in my case), then try to stay awake during the day, possibly taking a nap after lunch. Thank you for your time and knowledge.

Answer:

Right on! Keeping a consistent wake-up time seven days a week is very basic to a successful sleep hygiene routine. It is certainly better to wake up at your standard time after a late night out than to sleep in. This is especially true for people vulnerable to depression, because sleeping in can immediately trigger a downswing, which sometimes lasts for several days. You may well find by midday that you don’t require a compensatory nap, and if so, you should resist napping and build up sleep pressure for the next night. A similar issue often arises when a person has a problem with delayed sleep phase, hypersomnia (sleeping or too long a period), or both. When starting light therapy, it can be a challenge to awaken at the recommended earlier hour — although once the light therapy effect kicks in, it becomes easier. We have seen patients with the delay tendency who manage well during weekdays, with normal sleep, but fall apart on weekends: there is a motivational issue here, part of the depression spectrum . . . the tendency to conform to a normal day-night pattern only when it is “required.” Here, too, risk increases with sleeping in.