Regarding the relationship between dopamine, addiction and video games, Professor Olaf Paulsen of The Neurological Research Unit at Rigshospitalet is quoted for saying:
“The reason that some researchers focus on video games is that the brain activity while playing is easier to measure and standardize than in the case of complex task-completion and sports which cannot be measured in a scanner.
“Another reason that some researchers focus on video games and gambling is that this focus can fund their research. By positing a theory that video games and gambling create addiction because of dopamine, the researcher is able to apply for money from the so-called ludomania pool of Tipstjenesten [The Danish national game service].”
That theory seems less than implausable.