Problematic internet use is associated with poorer health behaviours and peripheral serotonin levels in young men

Problematic Internet Use (PIU) is associated with difficulties in psychological, social, academic, and occupational functioning and is associated with unhealthy behaviours such as poor diet, inactivity, and sleep problems. The post-pandemic period has intensified PIU and Internet addiction, especially among young men, who are more prone to risky health behaviours. This study aimed to assess the relationship between health behaviours, PIU, and serotonin and dopamine levels in young men. A cross-sectional study was conducted among 325 men aged 18–30 from the West Pomeranian region of Poland. PIU severity was measured using the Internet Use Test (IUT), and health behaviours were assessed using the Health-Related Behaviour Inventory (HBI). Blood samples were analysed for serotonin and dopamine levels using ELISA. 17.7% of participants exhibited high or very high PIU. One-third led unhealthy lifestyles. Higher PIU correlated with lower health behaviour scores, with a small effect size. The overall HBI score was moderately negatively associated with non-work Internet use during weekdays and weekends. In the low PIU group, healthy eating habits showed a moderate positive correlation with dopamine levels. The linear correlation analysis, after adjusting for age and BMI, revealed a weak correlation between IUT scores and overall HBI scores, HBI healthy eating habits, HBI positive mental attitudes, and serotonin levels. PIU was linked to poorer health behaviours. These findings underscore the importance of addressing both Internet use patterns and health behaviours in interventions, as they are closely interrelated in this demographic. Further research should explore the neurobiological mechanisms behind these associations.