Over-exposure to television and other electronic media during the teenage years may contribute to depression in young adulthood, especially amongst young men, according to a report in the February issue of the Archives of General Psychiatry. Depression commonly begins in adolescence or young adulthood, and many factors have been identified, including genetic inheritance, temperament and parenting styles. Media exposure is another prime suspect as teens spend on average eight and a half hours a day with electronic screens and gadgets.

Brian A Primack and colleagues used data from the US National Longitudinal Survey of Adolescent Health to determine media exposure among 4142 adolescents who were not depressed at the beginning of the study in 1995. The young people reported an average of 5.68 hours a day, including 2.3 hours of TV, 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 per cent) had developed symptoms consistent with depression -- and their odds increased with each hour of daily TV viewing. This incremental effect was greatest for those with higher total media exposure. Given the same amount of media exposure, young women were less likely to develop symptoms of depression than young men.

Exactly how does too much media produce this effect? The authors suggest several mechanisms: the media may replace time that would otherwise be spent on social, intellectual or athletic activities that may protect against depression; they might disrupt sleep, which is important formal cognitive and emotional development; and they may transmit harmful messages. ~ Science Daily, Feb 3