Video previews: http://abcnews.go.com/2020

DIANE SAWYER REPORTS ON THE OVERMEDICATION OF CHILDREN IN THE U.S. FOSTER CARE SYSTEM, ON "20/20," FRIDAY, DECEMBER 2

Plus: Katie Couric's Interview with Superstar Beyonc�

"ABC World News" anchor Diane Sawyer continues her reporting on the U.S. foster care system with a new series of reports - "Generation Meds." Following a year-long investigation, Sawyer and Sharyn Alfonsi uncover a startling reality: many foster children, even as young as one-year olds, are being prescribed powerful mind-altering drugs at alarming rates -- up to 13 times higher than that of other children. As part of its investigation, ABC News was given an exclusive first look at a groundbreaking two-year study by the General Accounting Office (GAO) which finds that the federal government has not done enough to protect America's foster children from being over medicated with these powerful drugs. Reports began airing on "World News with Diane Sawyer" on Wednesday, November 30, and will conclude with this special report on "20/20," FRIDAY, DECEMBER 2 (10:00-11:00 p.m., ET) on the ABC Television Network. Viewers who want to share their thoughts on the reports should use the twitter hash tag #FosterChange to join in the conversation.

PLUS: At just 30 years old, Beyonc� already has the career resume of a legend -- award-winning singer-songwriter, actor, fashion designer, model and now mom-to-be. Katie Couric speaks candidly to the multi-talented artist about her highly talked-about pregnancy, as well as performing in, producing, directing and choreographing her new concert film, "Live at Roseland: Elements of 4."

VIDEO PREVIEW: Beyonc� on pregnancy cravings and a bizarre airplane encounter. #Beyonce2020

http://abcnews.go.com/2020/video/beyonce-hot-sauce-pickles-15051379

"20/20" is anchored by Elizabeth Vargas and Chris Cuomo. David Sloan is executive producer.