Abstract
The widespread adoption of mobile phones in daily life has raised concerns regarding their impact on mental health, including among postpartum women. Considering the rising prevalence of postpartum depression (PPD) and the pervasive use of mobile phones in modern society, this study aimed to rigorously investigate the causal relationship between mobile phone use duration and the risk of developing PPD. Data were collected through an online survey assessing mobile phone usage and mental health among postpartum women. The survey's reliability and validity were evaluated using Statistical Package for the Social Sciences software. In total, 2015 participants completed the survey. To explore causal relationships, genetic data were sourced from open-access databases, and two-sample Mendelian randomization (MR) techniques were employed. Statistical analysis, including chi-square tests, revealed a significant association between higher mobile phone use and lower incidence of PPD. MR analysis supported these findings, indicating a protective effect of mobile phone use against PPD (P < .05 based on inverse variance weighting and the weighted median method). This MR-based study provides evidence that increased mobile phone use is associated with a decreased risk of PPD, suggesting that mobile phones could serve as an effective tool for PPD prevention. These findings highlight the importance of evidence-based evaluations of lifestyle factors in mental health research.