WASHINGTON (AP) – School systems in the Washington area are looking at later high school start times.

Advocates say the teenage biological clock is geared for later bedtimes and blame a lack of sleep for contributing to absenteeism, depression and poor academic performance.

School leaders in Anne Arundel and Howard counties announced recently that they are looking into the issue, joining Montgomery and Fairfax counties.

Advocates are also scheduled to discuss the idea Friday at the annual conference of the National Association of Secondary School Principals being held at National Harbor.

(Copyright 2013 by The Associated Press. All Rights Reserved.)