How to restore and maintain a healthy sleep pattern? Background: Some people over holiday periods or weekends get into sleep patterns that involve waking up very late in the day (e.g., 1pm), and then going to bed quite late (e.g.,, 4am). Such people can find it very difficult to bring back their sleep pattern to be in line with more regular day time rhythms (i.e., waking up between 6am and 10am). When earlier wake-up is attempted, this can result in feelings of fatigue and low mood.  Such attempts can even fail, when the person sleeps through the alarm clock.

General questions:


How can a sleep pattern be effectively re-aligned with normal day time rhythms?
What are effective strategies for maintaining a regular sleep pattern?
Is there any specific research on what strategies work best?
Yang et al. (2001) study this exact question. They administered 6 mg of melatonin on Sunday afternoon to subjects that had delayed sleep-wake schedules for the two prior days. They found that


  On Sunday, melatonin administration increased the sleepiness throughout the evening and reduced sleep onset latency at bedtime. On Monday morning, subjective sleepiness was decreased in the melatonin condition.


Kolla &amp; Auger (2011) deal with resetting the internal clock for jetlag and night shift workers. Even though the situation is not identical, I think their main recommendations for adjusting the internal clock are relevant:


  Exposure to bright light in the hours leading up to the patient’s minimum core body temperature tends to push the internal clock later in time, whereas bright light in the hours immediately afterward pushes the clock earlier in time. 


(minimum core body temperature is usually 2-3 hours before wakeup time).
So in other words, in order to re-align from wakeup at 1pm to 6-10am one should wake up as early as possible, and go out to be exposed to sunlight (or use an artificial light source).

They also discuss the use of drugs such as melatonin and caffeine. 

References


Yang, C. M., Spielman, A. J., D Ambrosio, P., Serizawa, S., Nunes, J., &amp; Birnbaum, J. (2001). A single dose of melatonin prevents the phase delay associated with a delayed weekend sleep pattern. Sleep, 24(3), 272-281. Full text PDF
Kolla, B. P., &amp; Auger, R. R. (2011). Jet lag and shift work sleep disorders: How to help reset the internal clock. Cleveland Clinic Journal of Medicine, 78(10), 675-684. Full text.