American teens are feeling more stressed, anxious and depressed than their parents or grandparents did, according to a new study. Researchers blame changing national values. The study analyzed data from more than 63,000 high school and college students between the years 1938 and 2007. They found that 85% of college students were worse off, mentally, than their forebears in the 1930s and ’40s—even though students in those days were dealing with such issues as the Great Depression and World War II. "When you talk about generational change—as this study does—it’s really about changes in the culture," says lead researcher Jean Twenge of San Diego State University. "These results suggest that as American culture has increasingly valued extrinsic and self-centered goals such as money and status, while increasingly devaluing community, affiliation and finding meaning in life, the mental health of American youth has suffered."

Marijuana is growing more popular among high schoolers, according to a new national survey released by White House drug czar Gil Kerlikowske Dec. 14. Nearly 21% of high school seniors smoked pot in the last month, up from 19.4% last year and 18.3% in 2007. Use among 10th graders also is on the rise, from 13.8% in 2008 to 15.9% this year. Part of the problem, Kerlikowske said, is that the dangers of marijuana use have lately been minimized. "When beliefs soften, drug use worsens," he said.

James Cameron’s much ballyhooed epic sci-fi adventure Avatar grossed $73 million its opening weekend in North America, falling short of the record for December debuts set by Will Smith’s I Am Legend ($77.2 million) in 2007. But add in an international box office take of $159.2 million from in 106 territories (the film has not yet opened in Japan, China, Italy, Poland, Argentina or Uruguay), and Cameron’s latest effort raked in an estimated $232.2 million in its first three days. Twentieth Century Fox is describing that number as the "highest original content (non-sequel, non-franchise) opening weekend ever."

QUOTE: "The experience of watching [Avatar] is to go on a journey to a new world, get chased around by creatures, learn to fly them—all that sort of thing. The technology goes away for the audience at that point. I don’t think the average viewer cares. When they see a Pixar movie, they don’t need to know about the hundreds of artists who slaved away at computers for years to make it. It’s just: Do I like this story? Do I like the characters? I think Avatar will work that way."

—Avatar director James Cameron

QUOTE: "Reviewing James Cameron’s Avatar seems somehow beside the point. The film’s arrival has been heralded for so long, and hyped so furiously, that making evaluative statements about Avatar is sort of like the three wise men reviewing the birth of Jesus: ’At last, a baby for the new millennium!’ Avatar is a baby both for and of the new millennium. It will change the way blockbuster epics are conceived and made, and the way we think about technologies like 3-D and motion capture."

—Slate movie critic Dana Stevens

What female actress’s movies grossed more than any other in the 2000s? You might be surprised to learn that it’s not Julia Roberts or Sandra Bullock. No, it’s 19-year-old Harry Potter star Emma Watson, whose movies in the last 10 years brought in a whopping $5.4 billion internationally.

Also having a good year: 20-year-old country singer Taylor Swift, whom AP voted Entertainer of the Year.

And then there’s British singer Susan Boyle. Not only does she have the year’s best-selling album, but the video clip of her performance of "I Dreamed a Dream" on Britain’s Got Talent was the most popular YouTube video of 2009. It was viewed more than 120 million times, far outpacing second-place finisher "David After Dentist," which was watched a mere 37 million times.

Parents may be talking to their children too late when it comes to the subject of sex. Among adolescents in 141 families in California, more than 40% had already had sexual intercourse by the time their parents initiated any conversations about safe sex, birth control or sexually transmitted diseases. That’s according to data gathered in the Talking Parents, Healthy Teens program, a study administrated by researchers from the University of California Los Angeles/Rand Center for Adolescent Health. Dr. Mark Shuster, one of the study’s researchers and chief of general pediatrics at Children’s Hospital Boston, said of the findings, "The results didn’t surprise me. But there’s something about having actual data that serves as a wake-up call to parents who are not talking to their kids about very important issues until later than we think would be best."

QUOTE: "I tried to lose my virginity when I was 7 years old … But it didn’t happen—so everybody doesn’t have to bug out. My mother and the babysitter whipped my a‑‑, but it didn’t knock me off my mission. … When I was 13, and I felt I was a porno star because I’d been watching porn for so long. In the Bronx you could get a hotel for an hour. I always had $20 or $30 to take a chick to a hotel. I’m proud to say I love sex. You might catch me in a porn store at any given moment—it ain’t nothing I’m ashamed of."

—rapper Sean "Diddy" Combs, in an interview with Playboy magazine (as reported by the Huffington Post)

The Parents Television Council has filed an indecency complaint with the Federal Communications Commission regarding a recent episode of Fox’s Family Guy. The episode, which aired Dec. 13, features a scene in which a stripper gives someone a lap dance. "Apparently Fox must believe that because the program is animated it can air anything it wants on Family Guy no matter how inappropriate or indecent," said PTC president Tim Winter.

QUOTE: "Dexter without Rita [the titular serial killer’s optimistic wife, who’s been murdered] is just an artistic choice. … But you know what isn’t an artistic choice? Pouring a gallon of fake blood on the floor and then sitting [their] infant down in the middle of it. I’m still struggling to get into the minds of the writers who could stand around on the set that day, snickering to themselves and shaking their heads and saying, ’Oh, this’ll get them! They’ll never forget this one, no sir! No one has ever seen anything quite so shocking as this before!’ … Personally, I’m out. Because not only did the show snuff out its last ray of sunshine, it did so in a way that felt like a direct act of hostility against the audience itself. Maybe we deserve it for watching in the first place. Or maybe this is the price those of us who can’t chuckle at absolutely everything under the sun will be forced to pay, over and over again in this spectacle-driven nightmare culture, for still having some shred of humanity deep inside us.

—Salon critic Heather Havrilesky, on the Showtime show Dexter’s fourth season finale