BACKGROUND: Smartphone addiction has been linked to adverse mental health outcomes, but its association with suicidal ideation (SI) and suicide attempt (SA) remains inconclusive. This systematic review synthesizes evidence on the relationship between smartphone addiction and SI/SA.

METHODS: We systematically searched PubMed, Embase, Web of Science, and the Cochrane Library from 1971 to August 2025 for peer-reviewed English-language studies examining smartphone addiction and SI or SA. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS: Eleven cross-sectional studies met inclusion criteria. Nine studies were conducted in South Korea, one in China, and one in the United States. Most studies (7/11) were high quality. Significant positive associations between smartphone addiction and SI were consistently reported across adolescents, college students, and young adults. A dose-response relationship was observed, with high-risk users showing greater SI odds (OR range: 1.14-4.57). For SA, significant associations were also evident in high-risk groups (OR range: 1.15-1.87). The relationship was moderated by synergistic factors such as stress and usage duration.

CONCLUSION: Smartphone addiction is significantly associated with increased odds of SI and SA across different populations. The relationship mostly exhibits a dose-response pattern, with higher addiction severity correlating with increased odds. These findings support considering problematic smartphone use in suicide prevention strategies across age groups.