Longitudinal Stability of Genetic and Environmental Influences on the Association between Diurnal Preference and Sleep Quality in Young Adult Twins and Siblings

Abstract

Overlapping genetic influences have been implicated in diurnal preference and subjective sleep quality. Our overall aim was to examine overlapping concurrent and longitudinal genetic and environmental effects on diurnal preference and sleep quality over ~5 years. Behavioural genetic analyses were performed on data from the longitudinal British G1219 study of young adult twins and non-twin siblings. 1556 twins and siblings provided data on diurnal preference (MorningnessEveningness Questionnaire) and sleep quality (Pittsburgh Sleep Quality Index) and between phenotypes were largely accounted for by genetic factors (explaining between 60%-100% of the associations). All shared environmental effects were non-significant. Non-shared environmental influences played a smaller role on the associations between phenotypes (explaining between -.06%-40% of the associations). These results suggest that to some extent similar genes contribute to the stability of diurnal preference and sleep quality throughout young adulthood, but also that different genes play a part over this relatively short time-frame. While there was evidence of genetic overlap between phenotypes concurrently and longitudinally, the possible emergence of new genetic factors (or decline of previously associated factors) suggests that molecular genetic studies focussing on young adults should consider more tightly specified age-groups, given that genetic effects may be time-specific.

Development of a Measure of Sleep, Circadian Rhythms, and Mood: The SCRAM Questionnaire

“…The negative correlation between Morningness and Depressed Mood aligns with data suggesting that evening-type individuals are more likely to experience depression, and report more severe depressive symptomatology (Abe et al, 2011 ; Chan et al, 2014 ). Morningness and Good Sleep had a moderate positive correlation, consistent with evidence that eveningness is associated with higher levels of insomnia complaints (Wittmann et al, 2006 ; Chan et al, 2014 ; Barclay et al, 2016 ). Consistent with some previous research (e.g., Roenneberg et al, 2003 ), Morningness on the SCRAM questionnaire was positively associated with older age and female gender (cf.…”

“…Sleep quality involves a subjective assessment of total sleep duration, sleep latency, wake after sleep onset, and qualitative interpretation of the depth and restfulness of the sleep period (Buysse et al, 1989 ). Sleep quality and circadian phase are interdependent processes with individuals high on morningness reporting better sleep quality (Wittmann et al, 2006 ; Barclay et al, 2016 ). Moreover, a stable circadian phase, i.e., having regular sleep times, has been found to improve sleep quality (Gruber et al, 2011 ; Harvey et al, 2011 ), and the circadian system regulates antidepressant and mood stabilizing medication pathways in the brain (McClung, 2013 ).…”

Sleep problems in university students – an intervention

“… 51 The lack of significant changes concerning the students’ chronotypes may be attributable to the fact that the chronotype is a relatively stable construct in young adults and that changes might need more time. 52 …”

The role of parental circadian preference in the onset of sleep difficulties in early childhood

“…It has been reported that maternal circadian preference during pregnancy is related to maternal sleep quality during pregnancy [17], which in turn may modulate the infant's sleep quality and development. Circadian preference is viewed as a rather stable and reproducible quantitative behavioral trait in humans [29], regulated by a set of genes that modulate the functioning of circadian clocks and subsequently the sleepewakefulness cycle [30,31]. Thus, such inherited factors might influence the development of infants' sleep.…”