Smartphone Use and Neurobehavioral Outcomes in Adolescents: A Systematic Review of Cognitive Performance and Sleep Disturbances

Abstract

Aim: To evaluate associations between adolescent smartphone-related behaviors and attention, inhibitory control, affective and behavioral symptoms, sleep onset, and sleep continuity, while separating smartphone-specific measurements from broader digital-media exposure.

Methods: Primary observational, longitudinal and intensive-monitoring reports published through March 2026 were synthesized narratively. The study-selection diagram records 1,678 identified records, 1,462 screened records, 75 full-text assessments and eight included primary reports. Heterogeneous effect estimates were not pooled.

Results: A five-wave cohort of 11,286 youths associated within-person increases in problematic social-media use with subsequent parent-reported attention-deficit/hyperactivity symptoms, primarily among males. Another prospective analysis of 8,119 early adolescents linked problematic phone/social-media involvement with later sleep disturbance and attention-related scores. In 425 adolescents contributing 7,591 person-nights, each additional minute of post-10-pm smartphone use above the individual average corresponded to 0.87 minutes later sleep onset (95% confidence interval 0.84–0.90) and 0.43 minutes less sleep (95% confidence interval −0.47 to −0.39). An objective 79-youth school-hours study observed mean checking frequency of 64.46 ± 32.83 times and an association with lower go/no-go inhibitory control (F[1,28] = 4.8; P = 0.04). Associations varied by exposure timing and measurement method.

Conclusion: The evidence more consistently identifies bedtime engagement, compulsive involvement and repeated checking than total phone ownership as correlates of selected sleep and attention outcomes. Most evidence remains non-experimental; developmental vulnerability and reverse causation are plausible.