The COVID-19 Pandemic: Age Differences in Sleep Quality and Mental Health Across 59 Countries

Stephanie A. Kolakowsky-Hayner¹, Jiabin Shen², Yelena Goldin³, Kristine Kingsley⁴, Elisabet Alzueta^5,6, Juan Carlos Arango-Lasprilla^7-9, Paul B. Perrin¹⁰, Fiona C. Baker^5,11, Fofi Constantinidou¹², Yelena Bogdanova^13,14

¹Magellan Federal, Silver Springs, MD, USA
²University of Massachusetts Lowell, Lowell, MA, USA
³JFK Johnson Rehabilitation Institute, Edison, NJ, USA
⁴Institute of Cognitive and Emotional Wellness, Westchester, NY, USA
⁵Center for Health Sciences, SRI International, Menlo Park, CA 94025, USA
⁶Autonomous University of Madrid, Madrid, Spain
⁷Biocruces Bizkaia Health Research Institute, Barakaldo, Spain
⁸Department of Cell Biology and Histology, University of the Basque Country, Leioa, Spain
⁹IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
¹⁰Department of Psychology, Virginia Commonwealth University, Richmond, VA, USA
¹¹School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
¹²Department of Psychology & Center for Applied Neuroscience, University of Cyprus, Cyprus
¹³Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA
¹⁴Physical Medicine & Rehabilitation, VA Boston Healthcare System, Boston, MA, USA

Correspondence: Stephanie A. Kolakowsky-Hayner, 111 Morgan Drive, Royersford, PA 19468, USA, Tel: +1-408-966-9151; E-mail: momof1plus4@yahoo.com

Abstract

Objective: To determine if there are pandemic-related sleep and mental health problems at different ages in the general population.
Design: Survey data were collected following a snowball sampling method via social media platforms and mailing lists.
Setting: General population
Participants: Participants included 6,882 individuals from the general population, from 59 countries.
Interventions: None
Main Outcome Measures: Children’s Revised Impact of Events Scale - 8 (CRIES-8); Depression, Anxiety and Stress Scale - 21 (DASS-21); Generalized Anxiety Disorder-7 (GAD-7); and Regulatory Satisfaction Alertness Timing Efficiency Duration (RU-SATED).
Results: The current findings show significant differences among age groups in sleep quality and mental health. The younger group (19-29 years) seemed to be the most impacted during the COVID-19 pandemic, reporting lower sleep quality and higher rates of trauma-related distress, stress, depression, and anxiety symptomatology during the lockdown.
Conclusion: The current findings underscore the importance of screening for and treating mental health and sleep problems in the global population, and particularly among younger adults.

Key Words: COVID-19, anxiety, depression, sleep quality, stress, trauma-related distress

Introduction

The pandemic created by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/COVID-19) outbreak has created unprecedented and persisting health, societal, financial, and lifestyle changes for people around the world. Governments made swift responses to curtail the spread of the disease and reduce its deadly effects. Treading into unchartered waters, most countries implemented severe restrictions in movement and lock-down measures. The term ‘social distancing’ was coined to promote the need for physical distance and reduction in social activities. Fear of the disease, changes in lifestyle, and social isolation created unprecedented circumstances and an increase in health care challenges including mental health concerns [1]. Studies from early in the pandemic revealed increased anxiety and depression rates, an increase of sleep problems, and reductions in quality of life [1-4]. The COVID-19 pandemic imposed a significant burden on populations across the globe, and resulting lockdowns and quarantine restrictions [5,6] had a significant impact on sleep quality and psychological/mental health worldwide [7,8].

Research on age differences has not always yielded consistent findings. In the general population, anxiety disorders tend to be most prevalent, followed by mood disorders, impulse control disorders, and substance use disorders, with the former two most widely examined as a function of age [9,10]. Most studies indicate onset in late adolescence/young adulthood, with a linear increase in prevalence into middle adulthood, followed by a slower plateaued prevalence in older age [11,12]. Older adults have been shown to have a lower lifetime and recent prevalence of depression, anxiety, and distress [9,10,13], with lower severity in older adults despite increasing comorbidity of physical disorders [14]. Blazer and Hybels [9] evaluated biological, psychological, and social factors associated with depression and concluded that while older adults have a greater biological risk for depression than younger adults, younger adults experience depression at higher rates, which the authors suggest may be due to socio-emotional factors that buffer older adults. Evaluation of specific symptom presentation revealed that older adults are less likely to experience worry [15], while younger adults endorse higher rates of cognitive symptoms of anxiety, depressive symptoms, and negative affect [13]. This suggests that, while there may be variation in symptom profiles that warrants examination and clinical consideration, younger adults appear to endorse higher rates of symptoms traditionally associated with psychological disorders and therefore may be particularly at risk for mental health issues during the COVID-19 pandemic.

In terms of sleep issues during the COVID-19 pandemic, a systematic review and meta-analysis involving thirteen countries reported the global pooled prevalence rate of sleep disturbance among all populations of 35.7% [7]. However, the association between age and pandemic-related changes in sleep quality is not yet clearly understood. A cross-sectional study of 2410 participants (Age: ≥17) conducted in China in March 2020 reported several independent factors associated with poor sleep quality, including older age (24 and older), anxiety, and depression [16]. While another survey of 1230 participants (Age: 18+) in Mexico performed during the first two months of pandemic isolation found that younger people (Age: 18-40) reported more sleep disturbances, while older participants (>40-year-old) showed only slight changes in sleep [17].

Despite this body of research beginning to document mental health and sleep issues common across the globe during the COVID-19 pandemic, as well as some initial studies suggesting that younger adults may be at greater risk for mental health issues and inconclusive findings of age differences in sleep problems, no large-scale, multinational study to date have systematically examined whether different age groups may be experiencing a differential mental health burden. As a result, the purpose of the current study was to examine sleep and mental health problems across age groups during the first phase of the COVID-19 pandemic. It was hypothesized that sleep and mental health problems would decrease linearly with the increasing age group.

Materials and Methods

Participants

Participants were recruited from the general population of 59 countries categorized by the World Bank geographical region classification system [18]. Demographics appear in table 1. The average age of participants was 42.3 years (SD = 13.9).

Procedure

The current study is a secondary analysis of cross-sectional data collected from a larger study [2]. Standardized and adapted measures were combined in an online survey in English, then translated into French, German, Italian, Spanish, and Turkish. Using a snowball sampling method, the survey was open April 19 to May 3, 2020 and was promoted on social media such as Instagram, Facebook, Twitter, and WhatsApp, as well as email lists. Participants were informed about the study aims before giving their informed consent. Participation was anonymous and voluntary—participants did not receive any monetary compensation for their participation. The study was approved by the Universidad Autónoma de Madrid Ethical Committee (Spain, CEI-106-206) and was conducted in compliance with the declaration of Helsinki. The average response time was 15 minutes.

Measures

Children’s Revised Impact of Events Scale - 8 (CRIES-8)

The CRIES-8 is an eight-item Likert scale (α =.88) measuring trauma-related distress including 2 subscales: Intrusion and Avoidance [19,20]. The CRIES-8 has been shown to have good reliability and validity in samples of children, adolescents, and adults aged 8 to 75 [21-23]. It has been translated into more than 20 languages and maintained its factor structure and validity after translation via associations with other indices of trauma and distress [24,25].

Depression, Anxiety and Stress Scale - 21 (DASS-21)

The DASS-21 is a psychometrically sound [26-29] measure of depression, anxiety, and stress. The current study only included the Depression (α =.91) and Stress (α =.91) subscales which measure hopelessness, low self-esteem, and low positive affect and tension, agitation, and negative affect, respectively.

Generalized Anxiety Disorder-7 (GAD-7)

The GAD-7 is a quick measure of anxiety and worry (α =.92). It has been shown to have strong reliability, construct validity, internal consistency, and convergent validity [30-33]. Total scores range from 0-21 with higher scores indicating more anxiety [30,31].

Regulatory Satisfaction Alertness Timing Efficiency Duration (RU-SATED)

RU-SATED is a 6-item 3-point Likert scale (α =.63) measuring sleep health including regularity, subjective satisfaction, alertness during waking hours, appropriate timing, high efficiency, and adequate duration [34]. With total scores ranging from 0-12, higher scores indicate better sleep health. This measure has been shown to have good item correlation, reliability, convergent validity and adequate internal consistency [35,36].

Data Analysis

In addition to descriptive statistics, chi-square and one-way ANOVAs were used to describe the sample and to determine differences between age groupings. Participants were categorized into four age groups: 18-29, 30-49, 50-64, and 65 and older. Data were analyzed according to six main areas of interest including sleep quality, trauma-related distress, stress, depression, and anxiety. A conservative alpha level of p < .01 was set to minimize the chance of a type I error. Analyses were conducted using SPSS version 26.

Results

Sleep Quality

Overall sleep quality was significantly (F (3, 6881) = 84.63, p < .001) different among age groups (Figure 1). Younger participants had far more sleep quality issues compared with older participants. As seen in table 2, younger groups tended to have worse overall sleep quality and scored poorly on several items on the RUSATED scale (regularity, satisfaction, timing, efficiency, and duration) than older age groups. Younger groups were also more likely than older groups to endorse taking sleep medications. While also statistically significant (p ≤ .001), a linear pattern of age was not clear with regard to alertness and the use of natural sleep aids or therapies.

Trauma-Related Distress

Regarding Intrusion and Avoidance Subscales (Table 3), younger participants had significantly (p < .001) greater symptom severity of trauma-related distress than the older age groups, with a linear decrease in symptom severity as each age category increased.

Stress

The stress subscale of the DASS-21 revealed significant differences among age groups (F (3, 6881) = 149.78, p < .001) (Figure 2). Younger age groups experienced significantly greater stress symptoms than the older groups. Younger groups tended to: find it harder to wind down; over-react to situations; feel like they were using a lot of nervous energy; feel more agitated; find it difficult to relax; feel intolerant of anything keeping them from getting on with what they were doing; and feel rather touchy (Table 4).

Depression

The depression subscale of the DASS-21 revealed significant differences between age groups (F (3, 6881) = 111.84, p < .001) (Figure 3). Younger age groups reported significantly more depression symptoms than the older groups. Younger groups were more likely to endorse feeling that they couldn’t experience any positive feelings at all very much or considerably (Table 5). Similarly, younger groups felt considerably or very much more downhearted and bluer than older groups. They were also more likely to endorse being unable to become enthusiastic about anything and feeling they weren’t worth much as a person. While no clear pattern emerged in the older groups, the younger was more likely to endorse finding it difficult to work up the initiative to do things, feeling that they had nothing to look forward to, and feeling that life was meaningless.

Anxiety

Based on the GAD-7 responses, there was a significant age difference (F (3, 6881) = 116.36, p < .001) with regard to anxiety symptoms (Figure 4). Again, younger groups tended to report an overall greater severity of anxiety symptoms. The younger groups were more likely than the older groups to endorse all seven GAD-7 symptoms more than half the days or nearly every day (Table 6).

Discussion

Age Differences in Mental Health

The current findings show significant differences among age groups in mental health. The younger group (19-29 years) seemed to be the most psychologically impacted during the COVID-19 pandemic, reporting higher rates of trauma-related distress, stress, depression, and anxiety symptomatology during the lockdown. This is in line with other cross-sectional studies in the general population that showed younger individuals are at higher risk of deleterious effects from the pandemic on mental health when compared with older adults [3,37,38]. A Canadian study showed how pandemic-related stress, anxiety, and depression rates were highest among those aged less than 25 and lowest amongst those aged more than 60 years old [39]. Longitudinal evidence assessing mental health and well-being during the pandemic among middle-aged and older adults in the United States showed psychological problems prevalence decreased with increasing age [40].

Despite COVID-19 posing a greater physical health threat for older adults – given its increasing age-related death rate – overall evidence indicates the younger individuals experience to a greater extent pandemic-related impacts on mental health. Exposure to media of the youngest, along with the life uncertainty brought about by the pandemic at this age might explain some of these differences [41,42]. On the other hand, older adults have been shown to have better emotional regulation, making use of more proactive coping, which may function as a resilience factor against pandemic-related stress [43,44].

Sleep and Psychological Consequences of COVID-19 Pandemic/Lockdowns

The current results indicated significant differences among age groups, with younger participants reporting more sleep quality problems than older participants. These findings are in line with a survey conducted in Mexico [17]. These results may reflect additional vulnerability of younger populations to social isolation and other factors such as employment and economic insecurity during lockdowns. A recent study identified poor sleep among other factors (e.g., depression, and anxiety) associated with suicidal ideation in university students (Mean age 21.4 years [SD = 1.9]) [45]. Another study reported that COVID-19-related anxiety correlated positively with insomnia severity and suicidal ideation [46].

Mental health symptoms and sleep disturbance may have a bidirectional association [7,47] and have important implications for mental health and sleep treatment planning and symptom management. The results of this study underscore the importance and necessity to both evaluate and treat/improve sleep quality, especially in younger age group, in the general population not only during this pandemic but also during the post-pandemic recovery period.

Interventions, Treatment Accessibility, and Support

Previous literature has identified social support as one of the protective factors and a potential intervention to improve sleep quality and reduce other commonly associated neuropsychiatric symptoms, including stress, depression, and anxiety [48,49]. A more recent report indicated that social support can improve sleep quality in self-quarantined people staying at home for 2 weeks due to COVID-19 restrictions [50]. Additionally, there are multiple telehealth and traditional treatments and techniques available, aimed to improve sleep quality, such as home-based treatments and relaxation techniques. Various mobile and web-based platforms/apps for self-assessment and sleep monitoring became more accessible and widely available for general public during the pandemic [51,52]. Future studies are needed to evaluate the effectiveness of mobile and web-based interventions to provide an evidence base for clinical recommendations and to inform the development of novel accessible treatments, targeting younger populations.

Limitations

The results of the current study should be interpreted in light of the following limitations: First, in this study, mental health was evaluated based on questionnaires that measured anxiety, stress, and depression. It is likely that there are also differences by age group in other variables related to mental health that were not included in this study; Second, due to the cross-sectional nature of the study, we do not know if age differences in the outcomes studied remain constant over time or if they were specific to the beginning of the pandemic when the current data were collected; Third, although, the study had a sample of participants from 59 countries, caution should be exercised when generalizing these results to countries in which the study was not carried out; Fourth, the selection of the four age groups was made at the discretion of the study authors, which could also have influenced the differences found among these groups; Fifth, it is possible that since this study focused on the impact of the pandemic on mental health, many of the people who decided to take the survey could have been experiencing mental health problems at the time of the study, while those not experiencing mental health problems may have decided not to participate. Despite these limitations, the sample was one of the largest and most geographically diverse collected to date on sleep quality and psychological adjustment during the COVID-19 pandemic. As a result, it powerfully transcends many of the small sample size and culturally idiosyncratic studies conducted investigating similar topics.

Conclusion

The current study was the largest to date to examine age differences in sleep quality and mental health during the COVID-19 pandemic. Robustly, younger adults reported higher mental health symptomology than older adults, despite older adults’ being at greater risk for adverse effects of COVID-19. The current findings underscore the importance of screening for and treating mental health and sleep problems in the global population, and particularly among younger adults. Future research is needed to examine why younger adults may be at such acute risk of psychological symptoms during the COVID-19 pandemic and to develop and deploy evidence-based interventions to reduce that symptom burden.

Acknowledgements

Publication of this article was supported by the International COVID-19 Task Force of the American Congress of Rehabilitation Medicine’s (ACRM) International Interdisciplinary Special Interest Group. We would like to thank the ACRM staff for supporting the Task Force, particularly Ms. Terri Compos. Additionally, we would like to thank Dilara Yuksel, PhD and Sendy Caffarra, PhD for their contributions to the parent study, as well as all of the participants.