While insomnia is the second most common mental disorder, progress in our understanding
of underlying neurobiological mechanisms has been limited. The present review addresses …

During the last decade quantitative and molecular genetic research on sleep has increased
considerably. New behavioural genetics techniques have marked a new era for sleep …

Study objectives Country or regional differences in sleep duration are well-known, but few
large-scale studies have specifically evaluated sleep variability, either across the work …

Background Sleep has a major impact on health, which makes it a relevant topic for
research and health practitioners. Research on sleep determinants, ie factors that positively …

Background Twin studies show moderate heritability of sleep traits: 40% for insomnia
symptoms and 46% for sleep duration. Genome‐wide association studies (GWAS) have …

Sleep is a complex physiological state, which can be divided into the non-rapid eye
movement (NREM) phase and the REM phase. Both have some unique features and …

Given that sleep deprivation studies consistently show that short sleep causes
neurocognitive deficits, the effects of insufficient sleep on brain health and cognition are of …

The manifestations of chronic insomnia undergo age-related changes. In younger infants
and children, behavioral insomnia emerges as the most prevalent form and typically …

This review explores the criteria used for the selection of genetic instruments of sleep traits
in the context of Mendelian randomisation studies. This work was motivated by the fact that …

Twin studies of insomnia exhibit heterogeneity in estimates of heritability. This heterogeneity
is likely because of sex differences, age of the sample, the reporter and the definition of …