Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing

The association of irregular sleep schedules with circadian timing and academic performance has not been systematically examined. We studied 61 undergraduates for 30 days using sleep diaries, and quantified sleep regularity using a novel metric, the sleep regularity index (SRI). In the most and least regular quintiles, circadian phase and light exposure were assessed using salivary dim-light melatonin onset (DLMO) and wrist-worn photometry, respectively. DLMO occurred later (00:08 ± 1:54 vs. 21:32 ± 1:48; p

• NS
  National Space Biomedical Research Institute

  Awards: HFP02801, HFP02802
• NI
  National Institutes of Health

  Awards: HL094654, P01-AG09975, NIH K24, R01-GM-105018, K24-HL105664, NIH R01, NIH K99