Sleep disturbances and anxiety disorders are becoming increasingly common. As mental health is beginning to be acknowledged as a prominent social issue, it is important to consider factors that could contribute to mental health concerns. A recent study by researchers at the Democritus University of Thrace explores the association between quality of sleep and anxiety disorders among various socio-demographics. The study not only discovered that reduced quality of sleep is closely associated with symptoms of anxiety but that anxiety disorders are also linked to reduced sleep duration (Serdari et al. 2020). This creates an endless loop, with sleep deprivation causing anxiety and anxiety again reducing the quality of sleep, which is hard to escape. This study also found symptoms of anxiety to be more prominent among minority populations. The study was one of the first to consider this often-overlooked perspective and consider socio-demographic, lifestyle, and health characteristics.
Before we understand the schematics of this research, there are some important scientific concepts and terms to understand. Along with losing the benefits of sleep, sleep deprivation has several consequences (Krause et al. 2017). Sleep is crucial to reducing anxiety overnight and recovering cognitive ability. It not only allows the body to rest but allows the brain to recover from intense use during the day. The amygdala and medial prefrontal cortex are two regions of the brain which are associated with fear and complex thought, respectively. Under ideal conditions, when a person sleeps at night, these brain regions are calmed physiologically. When sleep deprived, however, these regions are unable to properly recuperate and face high levels of stress, causing feelings of anxiety (Simon et al. 2019). Loss of sleep over long periods of time, therefore, has harsh effects on the brain and is linked to the development of anxiety disorders.
The current prevalence of anxiety disorders and worsening quality of sleep influenced the inception of this study. Although previous research has found information on the biological reasons behind the benefits of sleep loss and even explored the general correlation between sleep loss and anxiety disorders, there were not many studies that observed the effects of sleep deprivation on specific social demographics such as gender and ethnic minorities (Simon et al. 2019). To investigate both the connection between sleep deprivation and anxiety and the varying effects on different ethnic groups, Aspasia Serdari and several researchers conducted a cross-sectional study in which the researchers analyzed multiple variables and groupings of participants. Their study was funded by the Democritus University of Thrace and published by the Psychiatry Research journal.
This study population consisted of 957 adult participants who were selected through a stratified sample of all adults living in Thrace, Greece. The participants in this study were randomly sampled to ensure that the sample was representative of the general population of Thrace. Researchers obtained informed consent from all the study’s participants and followed the ethical standards of the Democritus University Ethics Committee. Using questionnaires, participants provided data on socio-demographic characteristics, lifestyle/dietary habits, and health characteristics. Participants also had to fill out a sleep questionnaire that asked when they normally went to bed, when they normally woke up, and how many hours they slept on average. These questionnaire answers were organized by week for a year, averaged by weekdays and weekends, and used to classify participants into categories based on their average sleep duration. Sleep disturbances and anxiety symptoms were assessed and self-reported by participants and then statistical analysis was performed to correlate sleep conditions with anxiety symptoms. Researchers hypothesized that shorter sleep duration and reduced quality of sleep would be more closely associated with anxiety disorders.
Through statistical analysis, this study confirmed the researchers’ initial hypothesis and found that sleep deprivation and anxiety were highly correlated. Researchers analyzed the association between anxiety and various sleep parameters, particularly sleep duration and sleep efficiency without adjusting the data, with adjustments for demographics, and with adjustments for lifestyle and health characteristics for each analysis. The results, assessed via linear regression, showed a statistically significant correlation between reduced quality of sleep to anxiety disorders. It was found that participants with anxiety typically went to bed earlier and woke earlier, had a slightly shorter sleep duration, and had reduced sleep efficiency compared to subjects without anxiety (Serdari et al. 2020). Not only was reduced sleep efficiency linked to symptoms of anxiety, but participants who suffered from anxiety were also more likely to fall into shorter average sleep durations, lower sleep efficiency, and had an increased risk for sleep disorders such as insomnia. In fact, participants with anxiety were over five times as likely as the average participant to fall into the shorter sleep duration group (Serdari et al. 2020). Results among various socio-demographics also showed disparities in the effects of sleep deprivation and anxiety. The researchers’ statistical analysis revealed a higher correlation between sleep deprivation and anxiety disorders among minority populations. In addition, males with anxiety reported shorter sleep duration and lower sleep efficiency than females with anxiety, indicating that certain sociodemographic groups are more susceptible to the harsh effects of sleep deprivation.
This study does have some limitations to be mindful of. The authors of this study admitted that there were restrictions in the size or scope of this study. Perhaps with more funding, similar studies could be replicated on a larger scale in the future. There were some additional points in the study where the results could be skewed. First, since the survey participants were volunteers, there could be voluntary response bias and a skew among the participants who chose to respond and participate. For instance, people who know they often do not sleep enough might not want to participate in a study related to sleep. Second, just above 70% of the people that the researchers reached out to participated in the study (Serdari et al. 2020). Though the researchers ensured that the sample was representative, this could affect the regions and groups represented in the study. Finally, the method of research may not be entirely accurate. Surveys are prone to response bias, as participants can provide inaccurate data, either accidentally or intentionally. For example, if someone did not track their sleep properly, that data point would be altered and could affect the observed trends in the data. However, it must also be understood that experimental studies can be difficult to ethically conduct in this field of research, and researchers often rely on observational studies. Overall, this study still collects data efficiently and ethically and these critiques likely had little effect on overall trends. Researchers also prioritized replicability, utilizing classification systems that are in line with those of other major studies in this field and establishing validity.
This correlation between anxiety disorders and quality of sleep, and vice versa, has larger implications. Though this study was conducted on a primarily Greek population, the observed biological concepts can be applied to all people. This study draws light on the importance of sleep, not just for rest and recuperation, but for mental health. Steps must be taken on both an individual and institutional scale to preserve sleep health. Members of underrepresented social demographics, minorities, and young adults should be particularly mindful of these study results, as they are most affected by anxiety disorders.
The results of this study support the notion that we, as a society, must combat mental health issues, before the devastating effects worsen. Too much pressure is placed upon individuals to compete and perform in various aspects of life. As a result, we are suffering from increasingly higher rates of psychological disorders, of which anxiety disorders are the most common, and sleep deprivation. These researchers’ findings indicate that there is a close connection between sleep and mental health, and a vicious cycle when either of the two is not prioritized. This study reinforces the value of sleep, tackling the current issue of mental health and understanding how different genders and ethnic groups respond to a similar biological occurrence. Researchers in this field should continue to include diverse social demographics to better understand varying effects.
References
Krause A, Simon E, Mander B, Greer S, Saletin J, Goldstein-Piekarski A, Walker M. 2017. The sleep-deprived human brain. Nat Rev Neurosci.18:404-418. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6143346/.
Serdari A, Manolis A, Tsiptsios D, Vorvolakos T, Terzoudi A, Nena E, Tsamakis K, Steiropoulos P, and Tripsianis G. 2020. Insight into the relationship between sleep characteristics and anxiety: A cross-sectional study in indigenous and minority populations in northeastern Greece. Psychiatry Res. 292:1-8. https://www.sciencedirect.com/science/article/pii/S0165178120318333?via%3Dihub.
Simon B, Rossi A, Harvey A, Walker M. 2019. Overanxious and underslept. Nat Hum Behav. 4:100-110. https://www.nature.com/articles/s41562-019-0754-8.
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