Cumulative Sleepiness

This is a great post on Dr. Weissbluth's blog (as you know one of my favorite sleep experts and author of Healthy Sleep Habits, Happy Child).  It talks about how a child can slowly build up a sleep debt over time until it comes to a head.  The solution is often, you guessed it, an early bedtime!  It seems like this is something a parent can often turn to time and time again.

Here is the post:
CUMULATIVE SLEEPINESS occurs when your child is a little short on sleep day in and day out. Small amounts of sleep loss add up and the effects of sleep deficiency or sleep deprivation increase. In the beginning, if the daily sleep debt is small, the adverse effects might be minimal at first but they grow and grow as the debt increases. Sometimes, an event such as an illness or three day week-end of messed up sleep throws the child over the edge and ”all of a sudden” sleep issues surface. Bedtime battles, night awakenings, early morning wake ups, or deterioration of naps develop. Often, these sleep issues start out as mild problems but they predictably grow into major sleep issues due to the accumulation of an ever increasing sleep debt. This is the explanation why parents are puzzled by their previously good sleepers suddenly going south.
There are some predictable patterns to recognize:
1. The bedtime is a little too late around 6-9 months of age when the third nap disappears, 12-21 months when the morning nap disappears, between 3-4 years when the single nap disappears.
2. The bedtime is a little too late during the summer time when the days are longer and you want to be outdoors in the evening.
3. Family vacations when naps are skipped or the bedtime is too late.