Depression, the leading cause of non-fatal disability worldwide, commonly begins in adolescence or young adulthood, according to background information in the article. "The development of depression in adolescence may be understood as a biopsychosocial, multifactorial process influenced by risk and protective factors including temperament, genetic heritability, parenting style, cognitive vulnerability, stressors (e.g., trauma exposure or poverty) and interpersonal relationships," the authors write. Media exposure is another plausible influence, since teens are exposed to an average of eight and one-half hours of electronic media per day.

Brian A. Primack, M.D., Ed.M., M.S., of the University of Pittsburgh School of Medicine, and colleagues used data from the National Longitudinal Survey of Adolescent Health (Add Health) to determine exposure to electronic media among 4,142 adolescents who were not depressed at the beginning of the study in 1995. The teens were asked how many hours they had spent during the last week watching television or videocassettes, playing computer games or listening to the radio (the survey was conducted before DVDs or the Internet became widely used). They reported an average of 5.68 hours of media exposure per day, including 2.3 hours of television, 0.62 hours of videocassettes, 0.41 hours of computer games and 2.34 hours of radio.

Seven years later (at an average age of 21.8), participants were screened and 308 (7.4 percent) had developed symptoms consistent with depression. "In the fully adjusted models, participants had significantly greater odds of developing depression by follow-up for each hour of daily television viewed," the authors write. "In addition, those reporting higher total media exposure had significantly greater odds of developing depression for each additional hour of daily use." Given the same amount of media exposure, young women were less likely to develop symptoms of depression than young men.

Media exposure could influence the development of depression symptoms through many different mechanisms, the authors note. The time spent engaging with electronic media may replace time that would otherwise be spent on social, intellectual or athletic activities that may protect against depression. Media exposure at night may disrupt sleep, which is important for normal cognitive and emotional development. In addition, messages transmitted through the media may reinforce aggression and other risky behaviors, interfere with identity development or inspire fear and anxiety.

"Psychiatrists, pediatricians, family physicians, internists and other health care providers who work with adolescents may find it useful to ask their patients about television and other media exposure," the authors write. "When high amounts of television or total exposure are present, a broader assessment of the adolescent's psychosocial functioning may be appropriate, including screening for current depressive symptoms and for the presence of additional risk factors. If no other immediate intervention is indicated, encouraging patients to participate in activities that promote a sense of mastery and social connection may promote the development of protective factors against depression."

This study was supported by a Career Development Award from the National Cancer Institute, a Physician Faculty Scholar Award from the Robert Wood Johnson Foundation and a grant from the Maurice Falk Foundation.

Note: If no author is given, the source is cited instead.

• Mental Health Research
• Children's Health

• Depression
• Mental Health

• Popular Culture
• World Development

• Adolescence
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• Sleep deprivation
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• Hearing impairment