Abstract
BACKGROUND: Poor sleep quality is common in depression, but complaints of poor sleep quality are not necessarily tied to objective sleep, and the construct of sleep quality remains poorly understood. Previous work suggests that beliefs about sleep may influence sleep quality appraisals, as might sleep variability from night to night. OBJECTIVE: We tested whether beliefs about sleep predict daily sleep quality ratings above and beyond nightly variability of actigraphy and diary-assessed sleep over the course of multiple nights. METHODS: Eighty-eight participants aged 18-65 years across a depressive continuum completed sleep diaries and reported their sleep quality and mood each morning; actigraphy was also completed for 67 of those participants. Multilevel models were used to test previous night's total sleep time and sleep efficiency as predictors of self-reported sleep quality (VAS-SQ) and mood (VAS-M), and whether unhelpful beliefs about sleep predicted VAS-SQ and VAS-M above and beyond the sleep variables. RESULTS: Individuals across a depression continuum with greater unhelpful beliefs about sleep reported worse sleep quality and worse mood upon awakening, even when accounting for nightly variation in actigraphy or diary assessed total sleep time and sleep efficiency. CONCLUSIONS: These results suggest that people are influenced by unhelpful sleep beliefs when making judgements about sleep quality and mood, regardless of how well they slept the previous night. Working with these unhelpful sleep beliefs in cognitive behavioral therapy can thus promote better sleep and mood in people across the depressive continuum.