Q. Our 11-year-old twins are falling behind in their school work. One of them fell asleep last night at dinner. It is a real struggle to get them awake and ready for school by 6:00 a.m. The doctor says they are healthy but thinks they need more sleep. We told them to go to bed at 10:00 p.m. and have all electronics turned off by 11:00 p.m. They claim that this is the time when they connect with their friends so they can’t turn them off. What do we do now?

A. What do you do now? You could step up to the plate and be wise parents, setting appropriate boundaries for your twins. This includes removing all TVs, computers, iPads, telephones, and other electronics from the bedroom. When they use electronics, they must do so in another room. Their bedroom is for sleeping. Period. Good grief, who is running the show at your house: the parents or two pre-teens?

The American Academy of Sleep Medicine advises that children aged six to twelve years of age need to obtain nine to twelve hours of sleep per night on a regular basis to provide optimal health. This means removing all TVs, mobile phones, iPads, electronic games or equipment from their bedroom(s), with a recommended non-use of all screen time an hour before bedtime. Average eleven-year-olds will find it difficult, it not impossible, to turn off electronics on their own. Electronics can be addicting. At age eleven, their brains need another nine or ten years before myelination of their corpus callosum—the largest of several bridges that connect the two brain hemispheres—is completed. Likely six to eight more years after that before their prefrontal cortex is developed enough for them to make healthy decisions on their own.

Because early adolescence is a crucial period for neurocognitive development, Dr. Wang and colleagues at the University of Maryland investigated how insufficient sleep affects the mental health, cognition, brain function, and brain structure in children ages 9-10 years old over a period of two years. Research showed that the brains of children who sleep less than nine hours per night had significant differences in specific brain areas compared with peers who slept nine or more hours per night. At the beginning of the study, brain imaging showed that children who sept less than nine hours per night had less grey matter or smaller volume in areas of the brain responsible for attention, memory, wellbeing, and inhibition controls. This finding persisted at the two-year-follow-up visit when participants were 11-12 years of age. Less than nine hours per night was also associated with an increased risk of depression, anxiety, and impulsive behaviors.

No wonder the American Academy of Pediatrics encourages parents to promote good sleep habits in their children. Their tips include making sufficient sleep a family priority, sticking with a regular sleep routine, encouraging physical activity during the day, limiting screen time, and eliminating screens completely an hour before bed. If your twins get up at 6:00 a.m., that means going to sleep at 9:00 p.m. In my brain’s opinion, the role of healthy parenting includes setting boundary limits that have been shown to enhance brain development during childhood, thus giving your twins a good start toward being successful and healthier throughout life. Adequate sleep is one of those boundaries.