Relationship Between Smartphone Usage Patterns, Sleep Quality, and Cognitive Function in Adolescents: A Systematic Review

Abstract

Aim: To assess associations between smartphone-use patterns, sleep quality and cognitive or academic outcomes among adolescents. Methods: Seven primary publications representing eight analytic samples were synthesised narratively. Exposure timing, problematic use and checking frequency were evaluated separately; effects were not pooled because exposure definitions and endpoints differed. Results: In a Turkish survey of 1,959 students, poor sleep quality affected 53.0% and problematic smartphone-use thresholds were met by 27.5%; the corresponding sleep correlation was r = 0.291. Intensive monitoring of 71 adolescents associated night-time, but not daytime, use with delayed sleep onset. A prospective cohort included 9,398 adolescents and linked bedtime phone behaviours with subsequent sleep outcomes. Among 79 youths, mean school-hour checking frequency was 64.46 times; checking was associated with weaker inhibitory control in a smaller tested subset (F[1,28] = 4.8, p = 0.04). A separate longitudinal cohort of 7,043 related sleep and broader screen exposure to cognitive-score change. Conclusion: Timing, bedtime access and repeated checking appear more informative than undifferentiated screen duration. Evidence for sleep-mediated cognitive impairment remains insufficient.