Sleep deprivation is a major public health problem . There are several things that can help improve sleep, such as buying a new mattress, limiting alcohol consumption in the evening, exercising regularly, and strictly using the bedroom for rest.
New research suggests there might be another ingredient, though harder to come by than a new mattress: being optimistic.
The study, which appears in the journal Behavioral Medicine , has found that optimists tend to sleep better. This is a finding that builds on previous studies that have suggested that optimists have better cardiovascular health.
Studying sleep and optimism
The researchers, led by Rosalba Hernández, an assistant professor at the College of Social Work at the University of Illinois at Urbana-Champaign, USA,examined 3,548 participants, ages 32 to 51, who participated in the Coronary Artery Risk Development Study in Young Adults (CARDIA).
Participants were non-Hispanic white and African-American adults living in Birmingham, Alabama, Oakland, California, Chicago, Illinois, and Minneapolis, Minnesota, among other regions of the US.
To assess the optimism of the participants, the experts asked them to express their agreement with a series of statements using afive-point Likert scale,ranging from “strongly agree” to “strongly disagree”. The statements included positive responses (“I’m always optimistic about my future”) and negative responses (such as “I hardly expect things to go my way”). The resulting survey score ranged from 6 to 30, with 30 being the most optimistic.
As part of the CARDIA study, participants reported on the quality of their sleep twice, 5 years apart, mentioning the number of hours they regularly slept and any symptoms of insomnia. Some participants also completedthe Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale, and they used activity monitors that objectively measured how long they were sound asleep and how restless they were during the night.
To assess the link between optimism and sleep quality, the researchers appliedmultivariate regression analysis.
Optimists are 74% less likely to have insomnia
The study revealed that each increase in the “standard deviation,” that is, the standard distance between two data points, was correlated with a 78% increase in the odds of better sleep quality.
Participants with higher scores were also more likely to sleep 6 to 9 hours each night and 74% less likely to have insomnia.
“The results of this study revealed significant associations between optimism and various sleep characteristics after adjusting for a wide range of variables, including sociodemographic characteristics, health conditions, and depressive symptoms,” says Hernández.
“Lack of [healthy] sleep is a public health problem, as poor quality sleep is associated with multiple health problems, including increased risks of obesity, hypertension and mortality from all causes,” adds the expert. “Optimism, the belief that positive things will happen in the future, has become a psychological asset of particular relevance to disease-free survival and better health.“.
Although the findings are purely observational, the study authors speculate about a possible mechanism that could explain them.
“Optimists are more likely to engage in active problem-focused coping and interpret stressful events more positively, reducing worry and reflective thoughts when they are falling asleep and throughout their sleep cycle,” Hernández concludes.
Referencia: Rosalba Hernandez, Thanh-Huyen T. Vu, Kiarri N. Kershaw, Julia K. Boehm, Laura D. Kubzansky, Mercedes Carnethon, Claudia Trudel-Fitzgerald, Kristen L. Knutson, Laura A. Colangelo, Kiang Liu. The Association of Optimism with Sleep Duration and Quality: Findings from the Coronary Artery Risk and Development in Young Adults (CARDIA) Study. Behavioral Medicine, 2019; 1 DOI: 10.1080/08964289.2019.1575179
