There are many possible factors that contribute to excessive gambling. This study was interested in the effects of loneliness, sense of mastery, and psychological distress on excessive gambling. The researchers hypothesized that psychological distress could be a mechanism by which loneliness and a low sense of mastery contribute to excessive gambling. They also wanted to know if this differed across four countries: South Korea, Spain, Finland, and the US. They surveyed 4816 people aged 15–25 in these countries. The researchers found that psychological distress was partially responsible for the effects of loneliness and low sense of mastery on excessive gambling. Low sense of mastery also independently predicted excessive gambling in all four countries. On the other hand, loneliness predicted excessive gambling in Spain and South Korea only.