Background: The prevalence of alcohol drinking (AD) in Croatian adolescents is alarming, but there is an evident lack of prospective analyses of the protective/risk factors of AD. This study aimed to prospectively investigate the relationships between scholastic and sport factors and harmful alcohol drinking (HD) in older adolescents. Methods: The participants (n = 644, 53.7% females) were 16 years of age at study baseline and were tested at baseline and again 20 months later (follow-up). The predictors included four variables of scholastic achievement and four factors evidencing involvement in sport. Criterion was AD observed on the Alcohol Use Disorders Identification Test (AUDIT), and results were later categorized into harmful drinking (HD) and non-harmful drinking (NHD). The HD at baseline, HD at follow-up and HD initiation during the study course were observed as criteria in logistic regression analyses, which were additionally controlled for confounders (age, gender, socioeconomic status, and conflict with parents). Results: With 22% and 29% adolescents who reported HD at baseline and follow-up, respectively, the prevalence of HD remains among the highest in Europe. Scholastic failure was systematically related to HD at baseline and follow-up, but scholastic variables did not predict HD initiation during the course of the study. The higher odds for HD at baseline were evidenced for current and former team sport athletes. Those who quit individual sport were more likely to engage in HD at follow-up. Longer involvement in sport (OR: 2.10, 95% CI: 1.18⁻3.72), higher sport result (OR: 3.15, 95% CI: 1.19⁻8.34), and quitting individual sport (OR: 13.13, 95% CI: 2.67⁻64.62) were predictive of HD initiation. Conclusions: The results indicated specific associations between sport factors with HD initiation, which is understandable knowing the high stress placed on young athletes in this period of life, mainly because of the forthcoming selection between junior (amateur) and senior (professional) level. The results did not allow interpretation of the cause-effect relationship between scholastic failure and HD in the studied period.
Keywords: educational achievement; physical exercise; puberty; relationships; substance abuse.