Great questions. The basic answer is YES, having an irregular sleep schedule can cause Social Jet lag, or what was previously called Sunday Night insomnia. Remember there are 2 distinct systems in the brain that make sleep happen. read more
Caffeine is a powerful stimulant, most commonly found in coffee, soda and energy drinks. Having a coffee too late in the afternoon can keep you awake for longer time. Nicotine, found in cigarettes and tobacco products is another stimulant that can cause insomnia. Smoking late at night can have a negative effect on your sleep patterns. read more
Moreover, as this age is usually the time of exploration and discovery among teens, this is when they start drinking, smoking, and staying out late with their friends. They may also start drinking coffee to stay alert during the day. These habits, though, can cause or aggravate insomnia in teenagers and may give rise to other sleep disorders. read more
So if a person truly can’t fall asleep before midnight but has to routinely wake up early, it's likely that sooner or later they're going to feel seriously sleep deprived. Late Nights Weaken Your Immune System. When I was in high school, the latest I'd stay up was typically 11 p.m. and occasionally, midnight. read more