A lot of buzz was generated by paper published last week in Pediatrics which found that seven-year-olds whose parents enforce regular bedtimes are better behaved than others without regular bedtimes.
Most commentators interpreted these findings as correlating insufficient sleep with poor behavior, and vice versa. That makes sense: Children without regular bedtimes usually wind up going to bed (and to sleep) at a later hour, thereby getting less sleep.
There’s another possibility, though, and that is that the parents who kept their kids on a regular schedule were better at setting (and maintaining) limits for their kids. Limit-setting is a very important part of parenting, and this is true not just with regards to bedtimes and sleeping patterns, but to dietary choices, doing chores, schoolwork, and interpersonal behavior as well.
This interpretation connects with the findings of another study published in 2010, which looked at the effect of parentally-set bedtimes and mood in teens. The researchers found that the later the child’s bedtime, the more likely the child was to have symptoms of depression and/or suicidal thoughts. While true that those with later bedtimes also got less sleep, those teens with earlier bedtimes tended to describe their parents as being more caring than those with later bedtimes. Children whose bedtime was set at midnight or later were 24 percent more likely to suffer from depression, and 20% more likely to have suicidal thoughts than children whose bedtimes were 10 p.m. or earlier.