Background: Empirical studies have shown that the relationship between psychological flow state and game addiction tends to be weaker in massively multiplayer online (MMO) games compared with non-MMO games. However, a theoretical explanation for the moderating effect of MMO games is lacking in the literature. This paper uses interview data and a method for generating hypotheses, literature-based discovery (LBD), to identify potential moderating factors and develop theories about this relationship. Methods: The proposed method involved text mining 2,829 abstracts to generate a keyword list of potential underlying moderating factors. Interview data from three domain experts confirmed the usefulness of LBD. Instead of arriving at game addiction primarily through flow, the interview data revealed that different cognitive pathways may lead to game addiction in MMO games. Results: Specifically, the identified keywords led to three explanations for the observed moderating effect: (1) social interaction in MMOGs may prevent the progression from flow to game addiction or induce positive peer influence; (2) game performance typically measured using a score- or point-based system in non-MMO games offers an extrinsic motivation that is more in line with flow theory; and (3) intrinsic motivation and escapism may be more important drivers of MMO game addiction. This paper summarizes the domain experts’ views on the usefulness of LBD in theory development. Conclusions: This paper uses literature-based discovery (LBD) to demonstrate how the pathways to game addiction in MMO games differ from non-MMO games. LBD is a method for generating hypotheses seldom used in the social science literature.