Playing a video game before bedtime has only a mild effect on the sleep of older male teens, a new study suggests.

Results show that after playing a stimulating video game, it took adolescents a median of 7.5 minutes to fall asleep, which was only slightly longer than the 3 minutes it took them to fall asleep after passively watching a documentary on DVD. Although no participants fell asleep while playing the video game, almost one-third of them fell asleep while watching the DVD. Subjective sleepiness after playing the video game was only slightly lower than after watching the DVD, and playing the video game was associated with a small increase in cognitive alertness. However, no significant differences in physiologic arousal or sleep architecture were found between testing conditions.

"Initially, we were surprised that playing the violent video game did not lead to a much longer time taken to fall asleep," said research supervisor Michael Gradisar, PhD, senior lecturer in clinical child psychology at Flinders University in Adelaide, South Australia. "Although the scientific literature is sparse when it comes to measuring sleep latency associated with playing video games, anecdotally a lot of people report difficulty falling asleep after playing video games at night."

The authors of the study, which appeared in the April 15 issue of the Journal of Clinical Sleep Medicine, concluded that the adage "everything in moderation" should guide parents as they set limits on bedtime video-game playing for adolescents.