The impacts of rumination and affective symptoms on subjective-objective sleep discrepancy

Prior research has shown a strong association between insomnia and affective symptoms including depressive and anxiety symptoms. Rumination, defined as repetitive negative thinking, impacts both insomnia and affective symptoms. However, relying solely on self-reported sleep measures, it remains unclear whether rumination and affective symptoms interact with their subjective-objective sleep discrepancy (SOSD) rather than perceived sleep duration per se. SOSD is defined as a mismatch between perceived and objectively measured total sleep time (TST). Negative SOSD (i.e. underestimating TST) is a phenotype of sleep disturbance that increases the risk of insomnia in daily life. Therefore, the cross-sectional study investigated whether trait anxiety and depression influence SOSD performance in the presence of rumination. We measured SOSD using sleep diaries and actigraphy over five days, and assessed subjective sleep quality, rumination, depression, and trait anxiety through self-reported surveys. We further classified 672 participants (20.66 ± 1.89 years old; 68.0% female) into three SOSD groups: underestimating (UE), correctly estimating (CE), and overestimating (OE) TST. The results showed that the CE and UE groups had similar rumination levels, whereas the OE group exhibited significantly lower rumination. We found no differences in depression or trait anxiety across SOSD groups. Linear regression models showed that greater rumination and affective symptoms significantly and separately predicted lower SOSD values, and females showed more underestimation TST compared to males. When rumination was included, neither depression nor anxiety uniquely predicted SOSD, regardless of sex, though each overall model remained significant. These findings suggest that depression and anxiety share overlapping explanatory variance with rumination in relation to SOSD outcomes among young adults and interventions targeting rumination and affective symptoms may hold promise for populations with negative SOSD, especially for females.