This week, several school districts in southern Maine became the first in the state to comply with guidance from health experts that adolescent students should not start the school day before 8:30 a.m.

The American Academy of Pediatrics and the U.S. Centers for Disease Control advise that starting school any earlier is unhealthy for teenagers.

As physicians and parents, we view the time change in Biddeford, Dayton, Saco and Old Orchard Beach as Maine’s ground zero for a health policy proven to have a measurable impact on the daily lives of thousands of children in other states.

Some districts, such as Westbrook, Cape Elizabeth and Cumberland, have made the move more gradually, shifting to 8 a.m. This is a great start, and we hope these districts can adjust toward the medically recommended 8:30 a.m. in future years.

According to the CDC, Maine’s average high school start time is 7:53 a.m., 10 minutes earlier than the national average of 8:03 a.m. and more than 30 minutes earlier than recommended.

Many of our middle schools start at 7:30 a.m. or earlier.

Decades of research supports the need for adolescents to sleep at least 8½ hours each night for optimal functioning and health. It is well documented that teens’ biological clocks are shifted about 90 minutes later than those of adults and younger children. That makes it physiologically very difficult for them to get enough sleep to meet the AAP recommendations and arrive at school for the early start times.

Most adults start to experience sleepiness around 9 p.m., when the pineal gland starts to produce melatonin, the hormone responsible for sleep-wake cycles. In the teen years, this production doesn’t start until closer to 10:30 p.m., which explains the familiar phenomenon of our 14-year-old “night owls,” who lie awake in the wee hours, long after parents have collapsed of exhaustion after a long day.

Adult melatonin secretion stops around 7:30 a.m., while our teens continue to have this sleep-inducing hormone pulsing through their bodies until as late as 9 a.m. Asking a teen to wake up at 5:30 a.m. for a school bus pickup of 6:15 a.m. is like asking adults to start every day at 4 a.m.

Out of necessity, many adults sleep less than we should, work overnight shifts and stay up later taking care of the home and children. But that still doesn’t make it healthy, and it is unfair to ask our children to do this at a time when their bodies and minds already are pushed to their maximum.

Early start times and inadequate sleep have been associated with poor academic performance, increased tardiness and absenteeism, increased traffic crashes for teen drivers, higher rates of athletic injuries and poorer health outcomes including obesity, depression and drug and alcohol abuse.

Hundreds of districts across the country have pushed middle and high school start times to 8:30 a.m. They have seen measurable improvements across many of these areas, with more students achieving the minimum recommended hours of sleep. The science is solidly in support of later start times, but the challenges for many communities lie in the details.

In our communities of Biddeford, Dayton, Saco and Old Orchard Beach, it took 18 months of planning, discussion, education and advocacy from our region’s physicians, administrators and parents before we implemented the new schedule. Parent inconvenience and human aversion to change can be powerful obstacles. We faced legitimate concerns over bus routes, before- and after-school care for working parents, sports schedules and mandated coordination with shared regional technology centers. While these issues needed to be vetted in the process of changing school times, all are modifiable factors that grownups manage every day.

By viewing early start times as a public health issue, our community was motivated to find solutions. Here are a few examples:

— To avoid increased transportation costs, we flipped the elementary and adolescent start times so that elementary students, whose brains are wired to awaken and learn much earlier than teens, started 30 to 45 minutes earlier.

— To accommodate families where older children were relied upon to care for younger siblings after school, our community partnered with local parks and recreation departments to expand affordable after-care for younger children and new programming for teens. School administrators also stepped up to provide more flexibility with drop-off times for working parents, ensuring that if a student must arrive at school for 7:30 a.m., they could eat a healthy breakfast and settle in before the first period bell.

— Athletic directors worked with neighboring communities to find creative solutions to sports schedules. This included scheduling the furthest travel games early in the season and using the last period of the day as a study hall, so athletes have the option for an early dismissal on the occasion of a long commute to a soccer match.

While it will take some time to fully measure the impact in our community, in the first week of school Biddeford High School student tardiness decreased by more than 60 percent compared to last year. Students are reporting they’re more awake and engaged.

Yes, there were the usual complaints all parents make when we have to adjust to a new routine, but at the end of the day that’s what happens every year at this time. At least this year we can transition back to school with the confidence that we’re going back to a healthier schedule.

Dr. Joan Pelletier is the school physician for the Saco/RSU 23 school districts. Tracey Ann Collins is the southern Maine chapter leader for Start School Later, a national grassroots organization advocating healthier school hours.