Prevalence and Associated Factors of Gambling Among High School Students in a Portuguese City.

Adolescent gambling has become increasingly prevalent with the rise of online platforms and the normalization of gambling behaviors. This study aimed to estimate the past-year prevalence of gambling among high school students in Viana do Castelo, Portugal, to investigate sex-related differences in gambling behavior, and to identify factors associated with gambling. A cross-sectional study was conducted in 2024 with 1064 students from the three existing high schools. Participants completed an anonymous online questionnaire covering sociodemographic data, gambling in the past 12 months and its characterization, substance use, and environmental influences. The primary dependent variable was past-year gambling, coded dichotomously as yes/no. Chi-square tests and logistic regression were used to assess associations between past-year gambling and the other variables. The weighted past-year prevalence of gambling was 35.0%, higher among males. Statistically significant sex differences emerged in gambling type, companions, expenditure, frequency, and mode of access. Compared with females, males were more likely to engage in sports betting and poker, gamble alone or with friends, spend more money, gamble more frequently, and gamble online only or both online and land-based. Multivariable analysis showed that being male, attending public schools, early tobacco initiation, frequent consumption of spirit drinks, and knowing others who gamble were independently associated with gambling in the past 12 months. Gambling is widespread among adolescents in this sample, with distinct sex-related patterns and strong social influences. Early prevention strategies should address both individual behaviors and broader social contexts. Longitudinal studies are needed to understand causal pathways and inform targeted interventions.