February 6, 2009

Too much TV ups depression risk

by Deborah Condon

Teenagers who are exposed to a high amount of television and other electronic media may be at an increased risk of developing depressive symptoms in young adulthood, the results of a new study indicate.

According to US researchers, the development of depression in adolescence can be influenced by many risk factors, including genetic susceptibility, exposure to stressors such as trauma or poverty, and parenting style. However media exposure is another plausible influence, as many teenagers are exposed to several hours of electronic media per day.

The team used data from a study of over 4,100 teenagers to determine their exposure to electronic media. None of the young people were depressed at the start of the study in the mid 1990s.

Each was asked how many hours they had spent during the last week watching television or videos, playing computer games or listening to the radio. (The study was initially conducted before DVDs or the internet became widely used.)

The teenagers reported an average of 5.68 hours of media exposure per day, including 2.3 hours of television watching.

Seven years later, the young people, now with an average age of 21, were screened for depression. Altogether, 308 were now displaying symptoms of depression.

The researchers found that the more television the participants had watched as teenagers, the more likely they were to have depression. However this risk also extended to other forms of electronic media.

"Participants had significantly greater odds of developing depression by follow-up for each hour of daily television viewed. In addition, those reporting higher total media exposure had significantly greater odds of developing depression for each additional hour of daily use,” the team from the University of Pittsburgh noted.

They suggested that media exposure could influence the development of depressive symptoms through many different mechanisms. For example, 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.

Furthermore 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 behaviours, interfere with identity development or inspire fear and anxiety.

"Psychiatrists, paediatricians, family physicians and other healthcare providers who work with adolescents may find it useful to ask their patients about television and other media exposure. 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,” the researchers added.

Details of these findings are published in the journal, Archives of General Psychiatry.

For more on depression, see…http://www.irishhealth.com/clin/depression/index.html