Substance use disorder (SUD), characterized by persistent inability to control psychoactive substance use leading to significant health, relationship, and academic/work problems, has recently been linked to digital addiction, particularly problematic smartphone use (PSU)—excessive smartphone engagement that impairs daily functioning and mental health. While existing studies consistently show connections between PSU, SUDs, and emotional distress, with some indicating PSU correlates with increased alcohol and cannabis consumption, these studies are limited by their focus on narrow substance ranges, oversimplified measures, and examination of only general associations without exploring specific influencing factors. Therefore, this study aims to investigate the relationship between PSU and SUD among university students while considering both individual factors (such as emotional problems) and contextual factors (like substance use patterns) to provide a more comprehensive understanding of how these behaviors interact.
The study surveyed 3,130 university students across Brazil using an online questionnaire that included sociodemographic information, alcohol-related measures (AUDIT, CAGE, DSM-5, TLFB), substance use assessments (ASSIST, DUSI), smartphone addiction scale (SAS-SV), and psychological symptoms (DASS-21). Data were analyzed using chi-square tests for categorical variables and appropriate tests for continuous variables, with network analysis conducted via Gaussian graphical model using the Graphical Lasso method to identify direct and indirect associations between smartphone addiction and substance use, employing four centrality metrics (betweenness, closeness, strength, and expected influence) to interpret network structure and variable relationships.
The study identified 46.9% of students as problematic smartphone users (PSU), who were more likely to be female, non-religious, living away from parents, and unemployed. PSU participants showed significantly higher substance use rates both in the past month (alcohol: 56.6% vs 46.4%) and past year (alcohol: 75.5% vs 63.1%, Cramer’s V = 0.13), with similar patterns for cannabis, amphetamines, and benzodiazepines, and scored significantly higher on AUDIT and DSM-5 alcohol use disorder criteria. Network analysis revealed strong correlations among alcohol assessment tools (AUDIT, CAGE, DSM-5) and between illicit substance uses, with alcohol consumption and stress emerging as the most central constructs in terms of strength and expected influence, while anxiety and depression demonstrated high betweenness and closeness centralities as network connectors, whereas smartphone addiction and cannabis use remained peripheral, with similar gender patterns observed except for slightly greater stress centrality among females. These findings highlight the critical role of alcohol consumption and emotional distress as key elements linking PSU with various substance use behaviors.
Takeaway: Problematic smartphone use is linked to increased substance use through alcohol consumption and emotional distress as key connecting factors.