Discussion

In the current study, a significant percentage of the population reported clinically important anxiety and depressive symptoms, whereas >45% suffered from clinically significant COVID-19-related PTSD symptoms during the lockdown measures. The vast majority of participants adhered to protective measures during the lockdown period and considered COVID-19 a serious, threatening, worrisome condition with a high possibility of transmission, especially without the application of protective measures. In addition, anxiety levels were strongly linked to female gender, educational level and increased perceived severity and worry about COVID-19, whereas depression levels were correlated with educational level, family status and increased perceived severity of personal situation in case of COVID-19 infection. Moreover, the direct psychological impact of the pandemic, as measured by COVID-19-related post-traumatic stress symptoms, was strongly associated with female gender, lower educational level, the presence of psychiatric disease history, the degree of COVID-19-related worry and adherence to protective measures. In contrast, chronic physical disease history, perceived infection risk and perceived efficacy of protective measures failed to independently predict participants’ psychological burden.

The high prevalence of PTSD, anxiety and depression symptoms reported in the current study corroborate previous research focussing on the psychological impact of the COVID-19 pandemic. Various studies from a wide range of ethnic and sociocultural backgrounds have shown that during the first wave of the pandemic, people experienced increased levels of anxiety, depression, post-traumatic stress, general psychological distress and insomnia.^{Reference Luo, Guo, Yu, Jiang and Wang3} According to a recent systematic review and meta-analysis, anxiety prevalence ranged between 8 and 55%, whereas depression prevalence ranged between 10 and 60%. Moreover, clinically significant post-traumatic symptoms were present in 30–35% of individuals.^{Reference Forte, Favieri, Tambelli and Casagrande17,Reference Tang, Hu, Hu, Jin, Wang and Xie18} According to our findings, the Greek population responded to the first wave of the COVID-19 pandemic and the lockdown measures mostly with a post-traumatic stress reaction, encompassing symptoms of intrusion, avoidance and hyperarousal and, to a lesser extent, with anxiety and depressive symptoms. Similar results have been reported by Wang et al,^{Reference Wang, Pan, Wan, Tan, Xu and Ho7} which showed that the prevalence of COVID-19-related post-traumatic stress symptoms was higher than the prevalence of depression and anxiety. According to recent population studies,^{Reference Forte, Favieri, Tambelli and Casagrande17,Reference Liang, Zhu and Fang19} COVID-19 can be considered a life-threatening disease which might cause PTSD symptoms. In this context, the outbreak of the pandemic in Greece and the accompanying lockdown measures probably acted as an acute psychological shock, which unexpectedly disrupted normal living, closely resembling the effect of acute psychological trauma. Earlier research focussing on epidemics showed that quarantine measures were associated with a high incidence of PTSD, similar to the incidence of PTSD symptoms following natural disasters or terrorist attacks.^{Reference Hawryluck, Gold, Robinson, Pogorski, Galea and Styra20,Reference Sprang and Silman21} Likewise, the COVID-19 threat and imposed lockdown measures have been associated with an increased psychological impact on the general population.^{Reference Mazza, Ricci, Biondi, Colasanti, Ferracuti and Napoli22}

Another important finding of the present study was that the Greek general population reported increased rates of high perceived COVID-19 severity, infection risk and efficacy of protective measures, similar to those reported by a recent Chinese study.^{Reference Lin, Hu, Alias and Wong23} In line with that, another large-scale study across three European countries (Germany, Italy and the Netherlands) revealed particularly high levels of perceived effectiveness of protective measures.^{Reference Meier, Glatz, Guijt, Piccininni, van der Meulen and Atmar24} In contrast, according to an online survey, Australians perceived the COVID-19 pandemic as less severe, themselves as less vulnerable to get infected and protective measures as less effective.^{Reference Seale, Heywood, Leask, Sheel, Thomas and Durrheim25} In addition, Lee and You^{Reference Lee and You26} reported low levels of perceived susceptibility to the SARS-CoV-2 infection in a large Korean sample. The aforementioned discrepancies in COVID-19-related perceptions might be attributed to cultural, societal and even political factors. During the study period, there was a wide-scale media coverage of the pandemic and an ongoing public awareness campaign regarding its effects, which may have contributed to people's increased awareness about the infection's consequences and the almost universal adherence to the protective measures. In addition, the detrimental effects of the pandemic in countries where a large number of Greeks live and work (Italy, England, USA), probably strongly shaped COVID-19-related public opinion, and convinced a large proportion of the population to conform to health authorities’ instructions and the recommended restrictive measures.

Our study also revealed that certain COVID-19-related perceptions were significantly associated with the emergence of psychological dysfunction. More specifically, the degree of COVID-19-related worry and the perceived severity of the infection were correlated with greater psychological distress, suggesting that during the first pandemic wave, increased disease-related awareness was linked to a heightened emotional reaction and a more severe post-traumatic stress response. The cross-sectional design of the current investigation did not allow us to draw safe conclusions regarding the direction of the observed associations, and further prospective research is needed to clarify whether people who perceived COVID-19 as a serious threat were more likely to experience psychiatric symptoms or whether people with a psychiatric vulnerability were more prone to feel worried and threatened by the pandemic. Nonetheless, adequate information around the pandemic and its severity, although disturbing and psychologically challenging, may contribute to a greater adherence to the recommended measures and eventually lead to more alert and responsible public health attitudes.^{Reference Wang, Pan, Wan, Tan, Xu and Ho7,Reference Rubin, Amlôt, Page and Wessely27}

As expected, female gender and lower educational level were strongly associated with increased psychological dysfunction. Women appear more vulnerable to the emergence of anxiety, depression and PTSD, and research on COVID-19 has repeatedly shown that the current pandemic is having a greater impact on women's mental health.^{Reference Luo, Guo, Yu, Jiang and Wang3,Reference Wang, Pan, Wan, Tan, Xu and Ho7,Reference Petzold, Bendau, Plag, Pyrkosch, Mascarell Maricic and Betzler28} School closure was one of the initial measures undertaken by the government during the first pandemic wave, and in most households, mothers probably experienced increased child care and family demands on a 24-hour basis and a complete shrinkage of leisure time. In addition, research has shown that women suffered greater job losses during the pandemic and faced greater work pressure and increased difficulties in balancing work and family life, thus becoming vulnerable to stress-related psychopathology.^{Reference Yerkes, André, Besamusca, Kruyen, Remery and van der Zwan29} Educational level has also been linked to individuals’ psychosocial adjustment, and during the lockdown period, people with a lower educational level might be more susceptible to the negative financial effect of the imposed restrictions. According to a recent meta-analysis, lower educational level has been identified as a significant risk factor for psychological dysfunction in the context of the COVID-19 pandemic across a wide range of relevant studies.^{Reference Luo, Guo, Yu, Jiang and Wang3} Apart from the association of educational level with occupational and socioeconomic status, less-educated individuals may be more prone to health-related prejudices, which might adversely influence their psychological adjustment during a public health hazard.

In the present study, the presence of mental disorder history was independently associated with the severity of post-traumatic stress symptoms. Alonzi et al^{Reference Alonzi, La Torre and Silverstein30} reported that people with a pre-existing physical or mental health condition were more vulnerable to the negative effects of the pandemic; however, in our sample, only mental and not physical chronic disease was associated with increased rates of post-traumatic stress. It is not clear whether this association may be attributed to social mediators, given that individuals with a psychiatric history may face several adversities (professional underachievement, financial difficulties, social isolation, family dysfunction) that render them more vulnerable to the effects of psychological trauma in general, or to a common biological background that involves altered neuroimmunity as a result of SARS-CoV-2 infection^{Reference Troyer, Kohn and Hong31} and a genetically dysfunctional hypothalamus-pituitary-adrenal axis.

This study has certain limitations. First, it was an online survey that was distributed mainly through social media, and for this reason, the present sample may not be representative of the general population, given that older or less-educated individuals may be underrepresented. Second, data on psychological functioning and disease-related perceptions were collected in the form of self-reported questionnaires, which do not possess the diagnostic accuracy of direct mental health assessments. In addition, we should note that, although our analysis revealed strong associations between certain parameters and the psychological impact of COVID-19, our prediction models explained a limited percentage of the variance in participants’ psychological symptoms, suggesting that there are additional, yet undetected, parameters that could be potential contributors to people's increased psychosocial vulnerability, and this should be sought in future research.

In conclusion, the current study provided useful information on the heightened psychological burden of the Greek population during the first COVID-19 lockdown period, and identified a set of risk factors associated with a greater COVID-19-related psychological impact. In the context of the serious shortcomings of the national healthcare system, the Greek authorities and the COVID-19 expert committee chose to face the first COVID-19 wave with gradual restrictive measures, escalating to a complete lockdown, quite early during the course of the pandemic, keeping the death toll at quite low levels.^{Reference Mazzucchelli, Agudo Dieguez, Dieguez Costa and Crespí Villarías32} The Greek strategy was indeed considered successful; however, it seems to have been accompanied by collateral damages, especially regarding the population's psychosocial adjustment. Based on the current findings, Greek policy makers should allocate healthcare and welfare resources to high-risk populations, including women, less-educated citizens and people with a psychiatric history, to alleviate the pandemic's detrimental consequences on people's psychological functioning. Prioritising the needs of these groups is of crucial importance to create a feasible and cost-effective preventive framework to cope with the second wave of the COVID-19 pandemic, which is now rising, especially under the present circumstances of economic restrictions.