Overview of findings

This is the first systematic review with meta-analysis to assess the prevalence of mental health symptoms in the adult general and high-risk populations of Southeast Asia during the Covid-19 crisis. It included 32 samples from 25 studies for an aggregate of 20 352 adult participants in a year of the Covid-19 pandemic. Our findings showed that the overall prevalence of mental disorder symptoms was similar among frontline HCWs (18%), general HCWs (17%) and students (20%) while being noticeably higher in the general population (27%). Factors contributing to adverse psychological outcomes among the general population could include increased exposure to Covid-19 information from the media30, 35 urban living30, 49 and higher levels of perceived susceptibility to Covid-19.51

The pooled prevalence rates of anxiety, depression and insomnia were 22%, 16% and 19%, respectively (Table 2). Anxiety was more prevalent in the general population than in HCWs and more frequent compared to depression in both groups (Table 3). Surprisingly, the overall level of moderate anxiety (21%) was not dissimilar to that of mild anxiety (26%). Regarding geographical distribution, there was a lower prevalence of depressive symptoms among the adults in the Malay Archipelago than those in continental Southeast Asia (7% vs 17%) despite comparable levels of anxiety (Table 3).

Table 3. Subgroup analyses of the prevalence of anxiety and depression Groups Subgroups Anxiety Depression No. studies 25 15 No. samples 32 20 No. prevalence 58 39 Total no. participants 20 352 13 960 Overall 22%, 95% CI: 19%–27%, I2: 99.9% 16%, 95% CI: 12%–20%, I2: 99.9% Population Frontline HCW 23%, 95% CI: 13%–34%, I2: 98.1% 14%, 95% CI: 5%–25%, I2: 98.5% General HCW 18%, 95% CI: 12%–80%, I2: 98.1% 15%, 95% CI: 10%–21%, I2: 97.5% General population 31%, 95% CI: 20%–44%, I2:99.7% 16%, 95% CI: 6%–29%, I2:99.7% Student 18%, 95% CI: 8%–32%, I2:99.4% 23%, 95% CI: 10–39% Severity Mild 29%, 95% CI: 21%–37%, I2: 99.1% 21%, 95% CI: 16–28%, I2: 98.2% Moderate 25%, 95% CI: 18%–33%, I2: 98.9% 14%, 95% CI: 10%–19%, I2: 96.6% Severe 8%, 95% CI: 5%–11%, I2: 95.5% 7%, 95% CI: 5%–10%, I2: 87.9% Instrument DASS-21 17%, 95% CI: 12%–24%, I2: 98.7% 14%, 95% CI: 10%–18%, I2: 97.7% GAD-7 21%, 95% CI: 12–31%, I2: 99.6% NA HADS 25%, 95% CI: 14–39%, I2: 97.8% 18%, 95% CI: 7%–33%, I2: 98.1% Region Continental 22%, 95% CI: 17%–27%, I2: 99.3% 17%, 95% CI: 13%–22%, I2: 98.9% Malay Archipelago 25%, 95% CI: 10%–45%, I2: 99.1% 7%, 95% CI: 2%–16%, I2: 96.5% I2 statistic indicates the heterogeneity. CI, confidence interval. Comparison of results with previous studies

The prevalence rates of anxiety, depression and insomnia are overall lower in Southeast Asia than those reported in previous meta-analyses and studies from other areas or countries during the pandemic. They are considerably lower than, for example, the rates reported by the same study group covering the first year of the pandemic in Spain (34%, 36% and 52%)53 and Africa (37%, 34% and 28%)54 as well as by a separate meta-analysis from China (26%, 26%, and 30%).14 Likewise, the pooled prevalence of anxiety (22%) and depression (16%) in Southeast Asia was found to be consistently lower than the recorded scores of 33% and 32% for anxiety and 28% and 34% for depression in the meta-analysis by Luo et al.55 from 17 countries (China, Singapore, India, Japan, Pakistan, Vietnam, Iran, Israel, Italy, Spain, Turkey, Denmark Greece, Argentina, Brazil, Chile and Mexico), and the meta-analysis by Salari et al.56 from 10 countries (China, India, Japan, Iran, Iraq, Italy, Nepal, Nigeria, Spain, and UK), respectively. Furthermore, the pooled estimates from Southeast Asia are lower than the mental health outcomes previously reported among the general population and HCWs during and after the MERS and SARS epidemics where high rates of mood symptoms and post-traumatic stress disorder (PTSD) were observed.32, 40, 43, 44, 46

The prevalence of psychological distress among students in Southeast Asia (20%), although deriving from a limited number of studies, compares favorably to that in Spain (50%),53 a meta-analysis performed on studies from China, Iran, India, Brazil and the UAE (28% pooled prevalence of anxiety)57 and a further meta-analysis from 31 countries performed by Deng et al. (anxiety 32%, depression 34%, insomnia 33%).58

The presence of mental health symptoms in HCWs in Southeast Asia follows a similar pattern compared with, for example, the first rapid systematic review and meta-analyses of 13 studies in HCWs from China, where more than one in every five healthcare workers suffered from anxiety or depression, with pooled prevalence rates of 23.2% for anxiety and 22.8% for depression.11 Subsequent reviews reported broadly similar rates including a meta-analysis of 19 studies and estimated rates of 26% for anxiety and 25% for depression.55 Even more surprising, however, was the finding that mental health concerns and anxiety symptoms in particular were more frequent in the Southeast Asian general population than HCWs. This pattern is at odds with previous observations elsewhere, whereby the rates were either similar or higher among HCWs compared to the general population during the same period of time. For example, Luo et al.55 found that rates were akin between healthcare workers and the general public; though noted that studies from a number of countries such as China, Italy, Turkey, Spain and Iran reported higher-than-pooled prevalence among healthcare workers. Similarly, in their review, Vindegaard and Benros59 concluded that HCWs generally appeared to experience more anxiety, depression, and sleep problems compared to the general population in a subgroup analysis of 20 studies. Furthermore, in our review, general and frontline staff recorded similar levels of psychological distress. Several previous studies demonstrated a higher psychological impact for frontline staff, yet others showed that the mental health effects of the crisis were equally felt across settings or specialties.60-62

Overall, anxiety symptoms were more frequent than depression, a common finding across most studies to date.55 Despite the considerable between-study heterogeneity, it appears that comparable proportions of respondents across groups recorded mild and moderate symptoms both for depression and anxiety, while more severe symptoms were less common. Additionally, Vietnam compares favorably against six other Asian countries (China, Iran, Malaysia, Philippines, Pakistan, Thailand) in a separate multinational study looking at anxiety and depression scores. The mean anxiety and depression scores using the Depression, Anxiety and Stress Scale-21 (DASS-21) were statistically significantly lower than all the six Asian nations.63

Although insomnia was underreported in the studies under the scope of this systematic review, it was evidently the least prevalent mental disorder in Southeast Asia at 19%. Moreover, this rate compares favorably to the levels of 36% reported in the meta-analysis by Jahrami et al.64 from 13 countries (Iraq, India, Germany, France, Italy, China, Mexico, Spain, Bahrain, Greece, USA, Australia, Canada) with further subgroup analysis highlighting the even greater frequency in Italy (55%) and France (51%). Overall, approximately two in five HCWs have been reported to experience some degree of sleep dysfunction,65 while shorter sleep duration has been associated with a higher likelihood of Covid-19 infection among HCWs.66

Practical implications

The results from this meta-analysis show that the rates of anxiety, depression and insomnia were lower in Southeast Asia compared to previous meta-analyses conducted in other areas. The disparity is particularly noticeable when compared to south European countries like Spain, France, Italy, and Greece.67 The differences between countries are likely multifactorial such as variation in pressures on healthcare systems, exposure to negative media and perceived lack of preparedness.68

In addition, the lower prevalence rates in Southeast Asia could be associated to the recent experience with epidemics and the use of early interventions similar to those in China and east Asia. Indeed, some useful lessons could be learned from the interventions which were deployed throughout this region. Vietnam, for example, was lauded for its testing and surveillance system which was used to identify infection sources69 and also recognized the importance of strengthening its grassroots healthcare system in order to contain Covid-19.70 In Singapore, the overall rates of preventative behaviors (e.g. avoiding public transport, social events and hospitals and reducing frequency/duration of shopping and eating out) were reportedly high,39 while another Singaporean study showed that the use of an official WhatsApp channel, providing information updates to the public, was protective against the development of depression.51 According to Luo et al.55 the use of precautionary measures to prevent the spread of Covid-19 and the access to up-to-date and accurate information were shown to shield from mental health problems.

Furthermore, a number of individual studies included in our systematic review, highlighted the mitigating role of higher levels of support against the development of anxiety symptoms. Among frontline HCWs, higher organizational and social support were both deemed to enhance resilience,32 and Sunjaya et al.50 underlined the importance of general HCWs to maintain frequent contact with peers and families to prevent negative mental health effects. Social, family and governmental support were found to be protective in the student population,52 while living alone was a risk factor.41 Furthermore, being single, separated or widowed was noted to be a risk factor within the general population33 alongside increased exposure to Covid-19 information from the media which was associated with a higher likelihood of anxiety.30, 35 A separate study reported that a dose–response correlation was observed between information exposure of three or more hours per day and the severity of affective symptoms.48 Though Cognitive Behavioral Therapy (CBT) was not utilized in any of the previously mentioned studies, it may help with the management of anxiety and depression caused by Covid-19.71 Additionally, internet CBT has been shown in one study to be a cost effective intervention72 while another highlighted its efficacy in the treatment of insomnia.73

Finally, there is a number of Southeast Asian countries such as Myanmar, Cambodia, Laos, East Timor and Brunei without any available large-scale data on the mental health effects of the pandemic. For these countries without country-level studies, our systematic review on Southeast Asia may help them to use the results at the regional level as relevant evidence to guide their practice including the development of national mental healthcare strategies for pandemic-related interventions and short, medium, and long-term service provision.

Strengths and limitations

To our knowledge, this systematic review is the first to examine the pooled prevalence of depression, anxiety, and insomnia in the general populations, HCWs and students during the COVID-19 outbreak in Southeast Asia. Despite the relative low number of studies per group and per country included in our meta-analysis, the total studies covered a considerable number of participants during a whole year of the pandemic. Furthermore, our subgroup analysis provided additional valuable insights of potential particular differences and /or vulnerabilities.

Nevertheless, there are some key limitations to our review. There was considerable disparity between the number of papers reporting on the four subgroups of populations, ranging from 14 (general HCWs), to nine (general population), six (frontline HCWs) and only three (students). In addition, only two papers evaluated the presence of sleep problems, thus limiting the power of the findings on insomnia. Again, the majority of studies were cross-sectional in design and conducted across inherently different countries at varying points in the course of the pandemic and some countries were not represented in this analysis which may limit the generalizability of our findings.

The COVID-19 pandemic was found to cause hemodynamic changes in the brain.74 This study mainly used self-reported questionnaires to measure psychiatric symptoms and did not make clinical diagnosis. The gold standard for establishing psychiatric diagnosis involved structured clinical interview and functional neuroimaging.75-77 Additionally, a variety of assessment tools were used to record the presence of mental health symptoms and different cut-off values were used to determine severity making it difficult to directly compare findings across studies. The quality of studies was also variable with high quality studies recording lower prevalence of mental health issues. Furthermore, non-English articles were excluded which could have created a bias. Finally, the studies included in our meta-analysis were all cross-sectional, thus the long-term physical and psychological implications of Covid-19 pandemic are not fully captured.