The vicious cycle of nighttime social media use and sleep procrastination in young adults: an ecological momentary assessment study

Objective This study tested the vicious cycle hypothesis – that nighttime social media use (NSMU) and poor sleep mutually reinforce each other over time – using ecological momentary assessment (EMA) among Iranian young adults residing in Arak city, Iran.Methods Sixty young adults (aged 18–25 years) from Arak, Iran, enrolled; 56 completed the full 14-day protocol (93.3% retention). Participants completed three daily EMA assessments (morning, afternoon, evening) plus a morning sleep diary, yielding four assessments per day. Participants reported their social media use each night (minutes), sleep onset latency (SOL), total sleep time (TST), and daytime fatigue.Results NSMU significantly predicted longer same-night sleep onset latency (b = 0.45, p < .001) and shorter total sleep time (b = −0.08, p < .001). Conversely, longer sleep onset latency (b = 0.80, p = .001) and shorter total sleep time (b = −12.30, p < .001) on a given night significantly predicted increased NSMU the next night, an effect partially mediated by daytime fatigue. Critically, both bidirectional effects intensified across the 14-day period (p < .01), demonstrating a self-reinforcing vicious cycle.Conclusions This study provides the first empirical evidence of a self-reinforcing bidirectional vicious cycle between NSMU and poor sleep in Iranian young adults using intensive longitudinal methods.