A large body of studies have focused on the potential health risks, both physical and mental, caused by heavy gaming. But the vast majority of these studies have focused on the young and adolescents, which makes a new study of gamers released by the American Journal of Preventive Medicine exceptional: its average participant was over 35. The research has made headlines as the media has interpreted it as indicating that gamers are "fat" and "depressed," but the research itself is too limited to support such generalizations.

One of the most obvious problems with such generalizations is that the study is based on survey data gathered online back in 2006. For whatever reason, it sat unused for two years before being analyzed in 2008, but it's important to note (given the conclusions about weight) that the Wii didn't hit the market until the end of that year.

The scope is limited, as well. The survey relied on an Internet-sourced panel maintained by e-Rewards Marketing Research. The authors selected participants in the Seattle area and, given an 18 percent response rate, wound up with 562 individuals, 249 of whom were gamers ranging in age from 19 to 90 years old.

This limited sample is not a definitive representation of gamers in general, and mainstream reports have ignored the study's own admission to this: "The fact that the sample was drawn from a population concentrated in western Washington State and from an Internet-based panel may limit generalizability of the results."

Indeed, western Washington has a climate that's rather unique within the US, one that may influence decisions on indoor vs. outdoor activities. Also, the survey population was demographically distinct from the general US population, having achieved higher levels of education and having a correspondingly higher average income.

The survey data was also completely dependent on self-assessment. Participants were asked to answer a variety of questions regarding their gaming and Internet habits, as well as their physical and mental health. Someone saying that they feel depressed some days and someone being clinically depressed are not the same thing. Furthermore, the standard deviation of the depression numbers in gamers was quite a bit larger than it was for nongamers, suggesting some outliers may be skewing the numbers here.

What few correlations are apparent in the data—a high Body Mass Index and an increased number of poor mental health days—the authors appropriately caution against inferring causality in the discussion, as well.

According to the self-reported gamer assessments, depression was higher in females than in males, while the potential weight issues were more likely to be seen in males; in both sexes, gamers were more likely to view Internet communities as part of their extended social support networks than nongamers.

The authors note that other studies have shown correlations with a sedentary lifestyle and weight problems in younger gamers as well, which may simply mean that this problem isn't age-specific. They also suggest that, among the depressed, gaming may be a form of what they term "digital self-medication," a way to keep their mind off the issues that are associated with the depression. This would seem in keeping with studies of EverQuest user data, which suggests a fraction of hardcore users rely on the game as part of an escape mechanism from a society in which they are marginalized.

The correlations are curious and more study is needed. For instance, the paper does not address the amount of time gamers spend gaming, nor is there any rigorous clinical backing to self-assessed claims about mental or physical health.

None of this is to say that gamers are "fat," "depressed," or anything but gamers. As with other behaviors which are often the subject of "self-medicating" theories, the what that someone is doing doesn't always point to the same why. Alcohol consumption, for instance, is routinely correlated with depressed populations, but this does not mean that all people who consume alcohol are depressed.

All in all, there's nothing radical about the paper's findings. The caveats are important to keep in mind; the study population was atypical, and comes entirely from a small geographic area. Although, on average, the population might self-report weight and depression problems, the standard deviations on these numbers were large, and easily overlapped with the average of the non-gaming population.

Of course, that list of caveats doesn't fit neatly into a typical headline.

American Journal of Preventive Medicine, 2009. DOI: 10.1016/j.amepre.2009.06.014