All living things have to cope with environmental changes and respond to challenges in order to survive. Every now and then, the quantity or difficulty of these trials can become too much and trigger a state of emotional tension or stress. Accumulating stress and unsuccessful attempts to tackle it can have a strong negative effect on wellbeing and mental health. or example, the COVID-19 pandemic, with its health risks, uncertainty, restrictions and other stressors, raised stress levels for many Estonians.

This article looks at the perceived stress levels among the Estonian population, including their changes both in the long term and in the context of the COVID-19 crisis. We will also present strategies that help people cope better with stress and reduce its negative effects.

There are many ways to assess stress and the ability to cope with it. In this article, we will rely on self-reported indicators of perceived stress from population-based studies. A self-report questionnaire is a convenient and valid tool for assessing the prevalence of stress, since the activation of a stress response depends in large part on how people perceive situations and stimuli (Roddenberry and Renk 2010).

More specifically, we will use data from the Health Behaviour among the Estonian Adult Population survey, which has been conducted every two years since 1990; the Estonian Biobank Mental Health Online Survey conducted in the spring of 2021 by the Estonian Genome Centre at the University of Tartu; the 2021–2022 Estonian National Mental Health Study; and the population-based survey Awareness of COVID-19 and Related Attitudes in Estonia (a COVID-19 rapid survey), conducted by the National Institute for Health Development in 2020–2021

Stress is the body’s natural response to environmental changes and challenges. The word ‘stress’ can have slightly different meanings in different contexts, but

here we use it to describe a relatively constant state of mental and physical tension that has been triggered in response to a perceived threat. The same definition is reflected in the questions that respondents are usually asked in self-report surveys measuring stress levels: “Have you been stressed, under pressure?” and “Considering everything that is going on in your life, how much stress have you experienced lately?“.

Stress is generally caused by the interaction of three components:

1. a stressor, i.e. a potentially dangerous stimulus in the organism’s internal or external environment;
2. perceiving the stimulus as exceeding the available coping resources;
3. a physiological and emotional response that mobilises resources to cope with the stressor.

Any change in the internal or external environment of an organism that can disturb its equilibrium can become a stressor (Selye 1976). In a narrower sense, this disturbance is caused by stressors that disrupt the body’s homeostatic equilibrium (defined as an appropriate range of temperature, fluid content or nutrients). In a broader sense, it is caused by stressors that threaten the achievement of a psychological goal, such as a short deadline for a work assignment, an important exam, or the fear of contracting COVID.

While environmental stressors are necessary for stress to occur, they alone do not trigger stress. The same situation – for example, self-isolation due to COVID – may cause stress in one person but not in another. This difference is due to the second component of stress, i.e. perceiving the stressor as exceeding available coping resources. Here, coping resources can be not only opportunities or skills but also various aids and people to turn to for help. Resources that help people cope with self-isolation, for example, include the possibility to work remotely and having time management skills. Therefore, a stressor triggers a stress response when the individual feels that the stressor poses a significant threat to them and that they lack the resources to cope with the stressor and keep the situation under control (Lazarus and Folkman 1984).

When perceived as a demand that exceeds available resources, the stressor triggers a series of interrelated changes in the body and mind. here are two main bodily systems that respond to it: the sympathetic nervous system¹ and the hypothalamic-pituitary-adrenal axis². Together, they produce wide-ranging changes throughout the body, increasing the heart rate and respiratory rate, raising blood pressure and blood sugar levels and increasing blood flow to the muscles, liver and brain. These changes aim to help the body mobilise itself in order to cope effectively with the encountered stressor.

A physical stress response is usually accompanied by mental changes. On the one hand, there is a sense of what people describe as unpleasant tension, worry and also stress. On the other hand, stress directs attention and other cognitive resources to processing information related to the situation. Just as the physical stress response helps the body prepare for exertion, mental changes related to stress help the mind to cope with the challenge being faced. As an unpleasant feeling, stress drives people to take action to relieve the tension they are experiencing. Investing cognitive resources increases the likelihood of that action having an effect.

Behaviours that are driven and amplified by the stress response are often effective, and as a result, the problem is resolved more quickly than under normal circumstances. Where such behaviour is ineffective, however, the person may experience a prolonged state of stress. A long-term or chronic stress response strains the body and increases susceptibility to various physical and mental illnesses.

In the Health Behaviour among Estonian Adult Population survey, perceived stress is assessed with a single question: “In the last 30 days, have you been stressed, under pressure?”. Figure 1.2.1. shows the prevalence of unbearable or higher-than-average stress levels based on the answers to this question, with 95% confidence intervals, among Estonian residents aged 16–64 in the period from 1990 to 2020.

library(tidyr)
library(ggplot2)
library(scales)
#faili sisselugemine ja andmete formaadi korrigeerimine
J121=read.csv2("PT1-T1.2-J1.2.1.csv",header=TRUE, encoding ="UTF-8")
names(J121)[2:17]=sub("X","",names(J121))[2:17]
J121d=J121[1:2,]
J121d=pivot_longer(J121d,col=names(J121)[2:17],"Year")
J121d$Aasta=as.factor(J121d$Year)

J121e=J121[3:6,]
J121e=pivot_longer(J121e,col=names(J121)[2:17],"Year")
J121d$Upper=numeric(32)
J121d$Lower=numeric(32)
J121d$Upper[1:16]=J121e$value[17:32]
J121d$Lower[1:16]=J121e$value[1:16]

J121d$Upper[17:32]=J121e$value[49:64]
J121d$Lower[17:32]=J121e$value[33:48]
J121d$value=as.numeric(J121d$value)
J121d$Lower=as.numeric(J121d$Lower)
J121d$Upper=as.numeric(J121d$Upper)


#joonis
ggplot(J121d)+
  geom_point(aes(x=Year,y=value,group=X,col=X),pos=position_dodge(0.2))+
  geom_line(aes(x=Year,y=value,group=X,col=X),pos=position_dodge(0.2),linewidth=1.5)+
  geom_errorbar(aes(x=Year,ymin=Lower,ymax=Upper,col=X),pos=position_dodge(0.2),width=0.3)+
  theme_minimal()+
  scale_color_manual(values=c("#1E272E","#FF3600"))+
  ylab("%")+
  scale_y_continuous(limits=c(0,35))+
  theme(legend.title=element_blank(),legend.position = "bottom")+
  theme(text = element_text(color="#668080"),axis.text=element_text(color="#668080"))+
  geom_smooth(aes(x=Year, y=value,group=X,col=X),method="lm",se=FALSE,linewidth=1.5,linetype="dashed")

## `geom_smooth()` using formula = 'y ~ x'

In 1990, 11% of men and 20% of women experienced unbearable or more than average stress. Six years later, these rates rose to 27% in men and 29% in women. During this transition period, stress was statistically significantly more common among women than among men. Additionally, this period marks the fastest increase and the largest relative change in the prevalence of stress among both men and women. After 2002, the prevalence of stress in men and women has more or less converged. Stress levels fell for both men and women until 2006 and started rising again from 2008 onwards. The economic crisis that broke out in 2008 is one possible explanation. That conclusion is reinforced by the statistically significant increase in the prevalence of stress from 2008 to 2010. While the prevalence rate of stress in men has decreased slightly since 2016, in women, a change was brought about by the COVID-19 pandemic, which reached Estonia in the spring of 2020 (at the time of data collection for the study). The pandemic might help explain why the prevalence of stress, which had remained at comparable levels among men and women after 2002, is now statistically significantly different again: in the spring of 2020, 17% of men and 24% of women experienced heightened stress levels.

Across age groups, the long-term trend and dynamic of the prevalence of stress is quite similar to the general trend. The rapid increase in the prevalence of stress among people aged 16–29 compared to other age groups is a notable exception. In 2018, for example, 28% of people aged 16–29 felt stressed, while the same was true for only 15% of those aged 50–64. Although age differences have decreased in the 2020 data, higher levels of stress are still most common among 16-to-29-year-olds.

Because very different situations and circumstances can act as stressors, there is no way to list all the possible sources of stress for Estonians. That is why we have chosen to focus on the stress caused by the COVID-19 pandemic. The pandemic offers a unique opportunity to observe how a single event experienced by the vast majority of Estonians affected their stress levels. We will use this opportunity to answer two questions: how much stress did the COVID-19 crisis cause in Estonians, and which aspects of the crisis most contributed to this stress? To answer these questions, we will use data from the Estonian Biobank Mental Health Online Survey, the Estonian National Mental Health Study and the COVID-19 rapid survey.

The first of the three studies offers an initial glimpse into the stress caused by the coronavirus pandemic. The prevalence of stress was measured with the question ‘Considering everything that is going on in your life, how stressed have you been lately?’ Figure 1.2.2 shows the share of people who experienced high and very high levels of stress by gender and age group. The results demonstrated that, on average, women experienced more stress than men (38% of women and 30% of men had experienced high or very high levels of stress). In addition, the experience of stress was highly dependent on age. Respondents with a high stress level were most common in the youngest age group (50% of women, 43% of men). The share of people with high levels of stress decreased in each subsequent age group, reaching the lowest level in people aged 75 and older (17% of women and 10% of men).