Researchers have found an association between electronic media exposure and the onset of depression in young adults, especially in males. Lead investigator Brian A. Primack, MD, EdM, MS, University of Pittsburgh School of Medicine, and colleagues analyzed public use data from the National Longitudinal Study of Adolescent Health (Add Health),1 and reported their findings in the February issue of Archives of General Psychiatry.2 Previous studies have reported on the effect of electronic media exposure on mental health, but “there is limited information about the relationship between media exposure and future development of depression in a nationally representative population,” according to Primack and associates.

The investigators explored the relationship between electronic media exposure in 4142 adolescents in grades 7 through 12 from 1995 to 2002 who were not depressed at baseline. To define a threshold for depression, the authors produced a 9-item depression scale, adapted from the 20-item Centers for Epidemiologic Studies—Depression Scale (CES-D) used in the Add Health study. Participants were asked to report hours of exposure to 4 categories of media—television, videos, computer games, and radio. Researchers quantified exposure to each media type as a continuous variable in hours per day.

The researchers reported 4 main findings: (1) of 4142 participants, 308 (7.4%) were found to meet symptom criteria for depression at follow-up 7 years later; (2) adolescents exposed to television had significantly greater odds of developing depression for each hour of daily exposure; (3) adolescents exposed to all 4 categories (total media) were at greater risk for developing depression for each hour of daily use; and (4) adolescent boys had significantly greater odds of developing symptoms of depression than girls given the same total media exposure.

Media use may take the place of social support and curb a teen’s desire to engage in real-life activities, which may partially explain why adolescents can develop depression when exposed to media for extended periods. Currently, it is estimated that adolescents multitask with various electronic media for more than 8 hours a day, according to Primack. This is quite a leap from the start of the Add Health study in 1995, when daily media use in adolescents was reported to be “only” about 5 hours per day.