Subjective sleep quality before and during the COVID-19 pandemic in a Brazilian rural population.

Objectives: Prior studies have examined sleep during the coronavirus disease 2019 (COVID-19) pandemic, but have few compared sleep measured both during and prior to COVID. We examined the impact of the COVID-19 pandemic on subjective sleep quality in general and separately by gender and age (<50 vs. ≥50 years).

Compared Heritability of Chronotype Instruments in a Single Population Sample.

It is well established that the oldest chronotype questionnaire, the morningness-eveningness questionnaire (MEQ), has significant heritability, and several associations have been reported between MEQ score and polymorphisms in candidate clock genes, a number of them reproducibly across populations. By contrast, there are no reports of heritability and genetic associations for the Munich chronotype questionnaire (MCTQ). Recent genome-wide association studies (GWAS) from large cohorts have reported multiple associations with chronotype as assessed by a single self-evaluation question.