A longitudinal investigation of sports betting legalization's influence on problem gambling.

As sports betting legalization expands across the United States, understanding its effects on problem gambling remains crucial for evidence-based policy development. This longitudinal study tracked 112 American sports bettors over two years using a natural experimental design, comparing problem gambling severity between participants in states that legalized sports betting during the study period versus those in states maintaining prohibitions. Mixed-effects negative binomial regression revealed no significant interaction between time and legalization status. However, equivalence testing failed to demonstrate that legalization's effect was practically negligible, leaving the true impact uncertain. Demographic analysis identified significant risk factors, with younger age and single marital status predicting higher problem gambling severity. These findings underscore the need for targeted protective measures for vulnerable demographic groups within regulatory frameworks in newly legalized jurisdictions.