Study evaluates impact of caffeine and technology on adolescent sleep time

Christina Calamaro considers adolescence as more than just a transitional stage between childhood and adulthood. She sees it as an opportunity for positive change.

"Adolescence is the last frontier before adulthood, a time when we can look at people's lives and make real dedicated change," says Calamaro, PhD, CRNP, assistant professor and director of the School's Primary Care Pediatric Nurse Practitioner master's specialty.

"There's an opportunity while people are still young to reinforce healthy behaviors as they move to becoming young adults."

Calamaro, who studies sleep and obesity in teens, uses what she learns from seeing families in the primary care clinic where she works to shape her research."My clinical setting is my laboratory," she says. "That's where I ask my questions."

When Calamaro learned from parents in her clinic that their adolescents weren't getting enough sleep, she went directly to the source.

The teens told her they were staying up late to e-mail, text, watch TV, and play computer games, all the while drinking lots of caffeine to stay awake. Aware that lack of sleep has been linked to obesity and depression, Calamaro wanted to learn more.

Researchers have for decades been studying the effect of increasing use of media at night and its impact on adolescent sleep time. But Calamaro's study, the results of which were published in June 2009 in Pediatrics, was the first to evaluate the consequences of caffeine and technology at night and their effect on adolescent sleep.

Working with data she gathered through interviews of 100 children ages 12 to 18, she discovered that the more nighttime multitasking teens did, the more caffeine they consumed, and the less they slept.

Eighty-five percent of the teens in the study drank caffeine daily, and 11 percent of those she studied drank more than 400 mg of caffeine daily—the equivalent of four espressos.

"It is not just about caffeine, it's about calories," she says. "When was the last time you saw a teenager walking into Starbucks and ordering a (no-calorie) espresso? It's usually a triple shot latte frappe." In the future, Calamaro says she'd like to explore how lack of sleep impacts decision-making among teens and how adolescents' lack of sleep relates to depression.