For almost as long as there have been video games, there have been people arguing that they are bad for you. There also seems to be a wealth of experimental evidence behind it (Hasan et al., 2013, to name just one of many). But there have been suggestions that these negative outcomes are oversold.
Problems with the literature:
One of the strongest pieces of evidence for the negative effects of video games is a meta-analysis by Anderson et al. (2010). They found strong evidence that “exposure to violent video games is a causal risk factor for increased aggressive behaviour, aggressive cognition, and aggressive affect and for decreased empathy and prosocial behaviour”. However, there were immediate questions about the methodology in this meta-analysis. Ferguson & Kilburn (2010) commented that many studies do not relate well to aggression and the authors do not consider the impact of unstandardised aggression measures (differences between studies in how they measured aggressive behaviour), among other things. They comment that the studies analysed in Anderson et al. (2010) only show weak evidence for their conclusion. A more recent reanalysis by Hilgard, Engelhardt, and Rouder (2016) used more advanced tools to adjust for research bias and found that the short-term effects of game play on aggressive feelings and behaviour were badly overestimated by bias. The adjustments recommended by Hilgard et al. (2016) were mostly substantially lower than those performed by Anderson et al. (2010), with some being smaller adjustments. In some studies, the result was adjusted to zero e.g. aggressive affect. This does not completely eliminate the original findings but I feel we should adjust our estimate of the strength of the causal association downwards.