When researchers looked at expression of a particular gene complex that is activated by chronic stress, they found differences depending on whether someone was positively engaging in video games or were problematic gamers.

For the American Journal of Human Biology study, investigators studied 56 people who play video games and compared those with positive and negative scores on a measure of social/psychological health related to gaming.

The study advances researchers' understanding of the "psychobiology" of play, demonstrating the association of negatively experienced internet play with biological measures of chronic threat, uncertainty, and distress.

"Our study finds that healthy gaming experiences are detectable in the body at the molecular level, with more favorable profiles of inflammatory and antiviral gene expression in immune cells from players who experience gaming as engaging rather than addictive," said lead author Dr. Jeffrey Snodgrass, of Colorado State University. "One striking finding is the way the gene expression results are influenced by gamers' relative degree of social connectedness to others. This is consistent with the idea that more problematic patterns of online play are importantly interrelated with the characteristic stress and distress of social isolation and loneliness."

The World Health Organization recently announced "gaming disorder" as a new mental health condition included in the 11th edition of its International Classification of Diseases