Objective Research has indicated potentially neutral or even positive cognitive effects of e-cigarette usage in adults, but whether these findings extend to adolescents remains uncertain. This study aimed to examine the interplay between e-cigarette use, mind wandering and self-efficacy, and mood. Method The responses of 432 adolescents aged 11-18 years from an online survey were analyzed. Among them, 88 adolescents had used e-cigarettes. Results Adolescents who have used e-cigarettes reported poorer academic self-efficacy, t (430) = 3.26, 95% CI [1.12, 4.51], p < 0.001; greater mind-wandering tendencies t(430) = −3.38, 95% CI [-4.14, −1.10], p < 0.001; and greater severity of depression, t(430) = −3.38, p < 0.001, anxiety t(430) = −2.67, p = 0.01, and stress t(430) = −3.32, p < .001. Increased frequency of e-cigarette use was also associated with attitudes toward e-cigarette use, r (86) = 0.31, p = 0.003 and lower academic self-efficacy, r (86) = −0.27, p = .010. However, there was no significant correlation between frequency of use and mind-wandering. Further network analysis suggested negative relationships between frequency of e-cigarette use, academic self-efficacy and mind-wandering. Conclusion Our findings suggest a potential adverse impact of e-cigarette use on mind-wandering and academic confidence among adolescents. However, the direct or indirect relationship between e-cigarette use and these effects could not be definitively determined due to the cross-sectional survey design employed in our study. Nonetheless, our findings underscore the importance of considering developmental differences and the unique vulnerabilities of adolescents when assessing the impact of e-cigarette use.