By Ben Smart and Liza Lucas, Special to CNN

Updated 2033 GMT (0333 HKT) August 7, 2015

School starts too early for teen

Middle and high school students are starting their school day too early, according to data published in the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report. The CDC and U.S. Department of Education researchers reviewed data from the 2011-2012 academic year and found that among the nearly 40,000 schools surveyed, 17.7% of public schools started school at the recommended time of 8:30 a.m. or later. Students in Louisiana had the earliest average start time (7:40 a.m.) while Alaska started latest (8:33 a.m.).

In 2014, the American Academy of Pediatrics recommended that schools start no earlier than 8:30 a.m., so teens can get more sleep. Sleepy students can suffer from poor grades and be at risk for depression and obesity. However, obstacles for moving school start times later include difficulties in scheduling after-school activities, as well as costs and traffic congestion associated with changing bus schedules, according to the report.

Autism screening for children under 3

The U.S Preventive Services Task Force says more research is needed on the benefits and potential risks of screening children younger than 3 for autism spectrum disorder before they can recommend it. The task force is an independent group of 16 experts who evaluate research regarding preventive medical services.

Right now, kids are screened for developmental disabilities, including autism, at 9-, 18- and 24- or 30-month well-child doctor visits. One study found that early detection and interventions could help children reduce developmental problems caused by autism. But the task force calls for more robust studies to better understand how screening affects childrens' health and development.

Some leading medical organizations aren't pleased with this recommendation. The American Academy of Pediatrics called the task force's findings "very disturbing." The academy warned it would be a "major step back" to stop screening in the interim. The recommendation draft is open for public comment until August 31, 2015.

I think students need sleep more time. As mentioned above, of nearly 40,000 schools surveyed, 17.7% of public schools start school at the recommended time of 8:30 a.m. or later. I hope we are going to sleep a lot!