Introduction

COVID-19 is an infectious disease caused by SARS-CoV-2 [1]. The first case of COVID-19 was reported in Wuhan, China, on December 31st, 2019, and afterward continued to spread across nearly 200 countries, causing an infection fatality rate of ~ 0.15% [2]. Considering the alarming levels of spread and severity, World Health Organization (WHO) declared it a pandemic on March 11th, 2020 [3]. Almost all the countries in the world provoked public health measures such as home confinement, closure of schools and universities, travel restrictions, and limit/ withhold social and physical distancing, while some countries declared it a public health emergency [4]. Many countries had to impose periods of lockdowns as an attempt to limit the spread of SARS-CoV-2. By early April 2020, more than one-third of the global population was under some form of movement restriction [5]. These strategies implemented in different countries intensively have caused substantial social and economic disruptions to individuals and the whole community [6]. While this disease has already directly impacted the physical health of millions of people, it is also causing mental health problems globally [7,8,9]. The evidence on the mental health harms caused by the response to COVID-19 found to be overwhelming, and studies on the general public revealed lower psychological well-being and higher scores of anxiety and depression compared to before COVID-19 [10]. The WHO also expressed its concern on the effect of COVID-19 on mental health and psycho-social consequences of an individual and it is estimated that COVID-19 pandemic triggers 25% increase in prevalence of anxiety and depression worldwide [11]. As new measures imposed in many countries such as self-isolation and quarantine, which affects day-to-day activities, routines, and livelihoods of people, they may lead to an increase in loneliness, anxiety, depression, insomnia, harmful alcohol and drug use, and self-harm or suicidal behaviour [12]. There is substantial evidence to demonstrate the deterioration of mental health among people during and after the COVID-19 pandemic compared to the pre-COVID-19 period [13,14,15,16]. Stack and Rockett (2021) discovered an increased suicide rate during the Spanish flu epidemic in 43 large cities, which was connected to the degree of social distancing, independent of the influenza fatality rate [17]. According to WHO, Every year more than 700,000 people die due to suicide [18]. However, there was no consistent evidence of a rise in suicide during and post-COVID era [19]. In this context, the research evidence on the effect of COVID-19 on suicides and suicidal attempts began to expand very rapidly. It is, therefore, timely and important to collate the global evidence on the incidence of suicide/suicidal attempts and the trend in suicidal rates during the COVID-19 pandemic. Thus, this study aimed to systematically review the available literature on (i) the incidence of suicidal attempts, suicidal deaths, and the trends in suicidal rates during the COVID-19 pandemic (ii) the risk factors for suicidal attempts and suicidal deaths during the COVID-19 pandemic, and (iii) the recommendations in preventing suicidal attempts or suicidal deaths during the COVID-19 pandemic.

Methods

Information sources and search strategy

The protocol for this systematic review was registered with the International Prospective Register of Systematic Reviews on May 5th 2021 (CRD42021253347). The Medline, Embase, and PsycINFO databases were searched for relevant studies from December 2019 to May 2021. The search strategy included a combination of keywords for COVID-19 and suicide/suicidal attempts. The language was restricted to English.

Study selection

Eligibility criteria for study inclusion were as follows: (1) studies that investigated suicidal deaths/ attempts of humans during COVID-19 pandemic (2) published after December 2019 and (3) adequately described the data on outcomes of suicidal death and suicidal attempts at any setting. Studies were excluded if any of the following criteria were noticed: (1) studies in languages other than English (2) study designs such as case studies, case reports, commentaries, editorials, letters to editor, reports, reviews, and systematic reviews, and (3) non-peer-reviewed articles and conference abstracts. The updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Also the review has conducted in accordance with Cochrane handbook for systematic reviews [20]. The studies yielded during the search were exported to the Endnote (EndNote X9. 3. 3 version) reference manager software. Following the removal of duplicates, screening against the inclusion and exclusion criteria was undertaken by two independent individuals in two stages; 1) title and abstract screening, and 2) full-text screening in Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia). Any discrepancies were resolved by consensus or by consultation with a third reviewer.

Data extraction

Two individuals extracted the data independently from the included full texts into an Excel spread sheet and cross-checked for further accuracy. Any discrepancies were resolved by consensus. Extracted information included the publication details (year, authors, country), characteristics of the studied sample (age, sex, and studied population), outcome variables (suicide deaths and suicidal attempts, method of suicide, previous history of suicide, and other risk factors reported), and recommendations to prevent future suicidal deaths or attempts.

Assessment of the quality of the studies

We assessed the quality of the included articles using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies [21]. The checklist contained fourteen items, including 1) Was this paper’s research question or objective clearly stated? 2) Was the study population clearly specified and defined? 3) Was the participation rate of eligible persons at least 50%? 4) Were all the subjects selected or recruited from the same or similar populations (including the same time period)? Were inclusion and exclusion criteria for being in the study prespecified and applied uniformly to all participants? 5) Was a sample size justification, power description, or variance and effect estimates provided? 6) For the analyses in this paper, were the exposure(s) of interest measured prior to the outcome(s) being measured? 7) Was the timeframe sufficient so that one could reasonably expect to see an association between exposure and outcome if it existed? 8) For exposures that can vary in amount or level, did the study examine different levels of the exposure as related to the outcome (e.g., categories of exposure or exposure measured as continuous variable)? 9) Were the exposure measures (independent variables) clearly defined, valid, reliable, and implemented consistently across all study participants? 10) Was the exposure(s) assessed more than once over time? 11) Were the outcome measures (dependent variables) clearly defined, valid, reliable, and implemented consistently across all study participants? 12) Were the outcome assessors blinded to the exposure status of participants? 13) Was loss to follow-up after baseline 20% or less? 14) Were key potential confounding variables measured and adjusted statistically for their impact on the relationship between exposure(s) and outcome(s)? Two reviewers assessed the articles against each of the 14 items independently and then cross-checked them. Any discrepancies were resolved by consensus.

Data analysis

Descriptive statistics were used to report the findings of included studies according to the research objectives. Tables and graphs were used accordingly to present the details of the publication, characteristics of the sample and outcome variables. Common themes were identified and reported in presenting future recommendations for preventing COVID-19 related suicidal deaths and attempts.

Results

Based on the database search, 1663 articles published between December 2019 and May 2021 were retrieved, and 611 duplicates were removed. Out of 1052 studies, 942 were excluded during the title and abstract screening. Subsequently, 110 full articles were screened at the full-text screening stage, and 18 were included. The main reasons for exclusions were different study designs, suicidal risk/ ideations, and inadequate information. The study flow chart outlines the detailed review process (Fig. 1).

Fig. 1
figure 1

PRISMA flow chart of included studies

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Characteristics of included studies

The main characteristics of the included studies are listed in Table 1. Some of the studies’ studied samples were composed only of suicidal attempts or suicidal deaths [22,23,24,25,26,27,28,29], while some of the studies included a wider sample to see the incidence of suicidal deaths and suicidal attempts [30,31,32,33,34,35,36,37,38]. The sample sizes of the studies that included only the suicidal deaths or suicidal attempts were ranged from 53 to 17,794. Sixteen (16) studies (88.9%) had a cross-sectional design and two studies [24, 26] have followed cohort design. Out of 18 studies included, 8 (44.4%) were from the United State of America [22, 24, 26, 30, 32, 34, 36, 38], 4 (22.2%) from Japan [25, 27, 29, 35], 2 (11.1%) from India [23, 37] and 1 (5.6%) each from Austria [31], Canada [33], German [28] and Nepal [39].

Table 1 Characteristics of included studies
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Incidence and the trends of suicide/suicidal attempts during the COVID-19 pandemic

12,746 suicidal attempts and 33,345 suicidal deaths were reported during the COVID-19 pandemic in the included studies. One other study has not reported separate data for suicidal attempts and deaths (n = 55), while one has presented rates. Because of the different durations used for data collection during the COVID-19 pandemic and the previous year (for non-COVID time comparison), it was unable to estimate or compare the suicidal incidence rate or to pool the data together for a meta-analysis. 16.7% (n = 3) of studies have no reported data on suicidal attempts or suicidal deaths trends. Regarding trends in suicidal attempts during the COVID-19 pandemic, an increasing trend was reported in 22.2% (n = 4) studies, while a decreased trend was reported in 11.1% (n = 2) studies. 5.6% (n = 1) of studies reported no increased or decreased trend in suicidal attempts. An increasing trend of suicidal deaths during the COVID-19 pandemic was found in 16.7% (n = 3), while decreased in 5.6% (n = 1) studies. 16.7% (n = 3) of studies reported no increased or decreased trends in suicidal deaths. Finally, 5.6% (n = 1) of studies reported decreased trends during the crisis but increased after the immediate crisis had passed (Table 2).

Table 2 The impact of the COVID-19 pandemic on suicidal attempts, death rates and trends
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Risk factors associated with suicide/suicidal attempts during COVID-19 pandemic

Out of 18 studies included in this systematic review, only six studies [22, 23, 27, 30, 33, 39] provided data on associated factors for suicide and/or suicidal attempts during the COVID-19 pandemic. The mental health impact of social distancing was reported as an associated factor by Ammerman et al., 2021, while COVID-19 quarantine was mentioned as an associated factor identified by Daly et al., 2021. Three studies [23, 27, 39] reported that financial crises due to loss of employment are associated with suicide and/or suicidal attempts during COVID-19. Table 3 shows the reported associated factors of suicide/suicide attempts during the COVID-19 pandemic.

Table 3 Risk factors associated with suicidal deaths and suicidal attempts
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Recommendations for prevention of suicide/suicidal attempts during the COVID-19 pandemic

Recommendations for preventing suicide/suicide attempts were provided in nine studies [23, 25, 27, 28, 30, 31, 33, 35, 37]. Of them, we have identified common thematic recommendations for preventing suicidal deaths and suicidal attempts, and those were; 1) Develop a systematic suicide screening process and increase the suicide risk screening [23, 25, 28, 30, 37]. 2) Facilitate communication and increase access to the interventions for the people at risk [30, 35], 3) Design, develop, and provide interventions for mental health and psychological well-being for the people at risk (including mental health awareness programs, promoting social connectedness) [23, 30, 31, 33, 35, 37] 4) Implement measures to mitigate the impact on the economy (e.g., Provision of economic supports and changes in payment policies) [35, 37], and 5) Regulation of media reporting [27, 37]. The study done by Nomura et al., 2021 in Japan revealed an increased rate of suicide among women. Therefore, they recommended feasible ways of strengthening the financial condition of women by providing direct income support, cut down of tax, postponement or exemption of social security payments for temporary workers, support for women's income security to end the gender pay gaps and regulations to correct the under-valuation of women’s work, and provision of paid leave and flexible working arrangements [27]. Ammerman et al., 2021 stress the need of empowering suicidal risk screening to identify those who are at risk [30]. One potential option to facilitate large-scale risk detection is to incorporate suicide risk screenings into the protocol at COVID-19 testing sites, as the routine screenings are not possible due to the social distancing and stay-at-home regulations. This may be accomplished by including one- or two-question screener that would result in a follow-up phone call to facilitate care linkage if a suicide risk is recognized [30]. Recommendations for preventing suicide/suicidal attempts during the COVID-19 pandemic suggested by individual studies are shown in Table 4.

Table 4 Recommendations for preventing suicidal deaths and suicidal attempts
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The quality of the included studies

In terms of the quality of included studies, six criteria out of 14 (43%) were satisfied by almost all of the included studies. Those criteria were; clearly defined research objective/s, clearly defined study populations, selection of subjects from a similar population, sufficient time frame, clearly defined exposure measures and clearly defined outcome measures. More than 80% of the studies have not measured the exposure before outcomes and adjusted for confounding variables. More than 40% of studies measured the exposure more than once over a time. Lastly, there were five criteria (36%) that we could not determine the quality or not applicable to assess the particular criteria in almost all the studies. Those criteria were; over ≥ 50% participation rate of the eligible person, having a justified sample size, having a different level of exposures as related to the outcomes examined, having blinded assessors of outcome/ s to the exposure status, and having a ≤ 20 follow-up from baseline (Fig. 2).

Fig. 2
figure 2

Quality assessment of included studies

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Discussion

This systematic review presents several vital factors based on more than 12,746 suicidal attempts and 33,345 suicidal deaths reported during the COVID-19 pandemic. Suicidal death is a preventable loss that disturbs families, communities, and countries. Globally, it is a significant public health problem, and more than 700 000 people die due to suicide every year [40]. The present review found that the majority of the studies reported an increasing trend of suicidal attempts during the COVID 19 pandemic compared to the rates reported before the pandemic. Nevertheless, a review done in 2020 to find the suicidal behaviors and ideation during emerging viral disease outbreaks before the COVID-19 pandemic found weak evidence to suggest a significant increase in suicidal attempts and deaths by suicide during emerging viral disease outbreaks [41]. Compared to the global past pandemics, COVID 19 has tricky and complex mechanisms that have facilitated its rapid and catastrophic spread worldwide [42]. It is considered the most severe pandemic of the twenty-first century [43]. The rise in community distress due to the unexpected spread and rise of covid-19 virus has led to a pandemic status, eventually may have caused for the increasing trend of suicidal attempts reported during the COVID 19 pandemic compared to similar pandemics the world experienced before.

According to the WHO, a prior suicide attempt in normal circumstances is considered the most critical risk factor for suicide in the general population. However, the present systematic review reported domestic conflicts and violence, financial loss/job loss, anxiety and depression, and pre-existing mental health condition/s were there among the identified risk factors for suicidal attempts and suicidal deaths during the COVID-19 pandemic.

The social restriction practices and policies imposed by different countries secondary to the COVID 19 pandemic might have negatively influenced the fore-said risk factors that has been indirectly led increased rates of suicidal attempts and deaths. Moreover, in the wake of COVID 19, millions of people lost their access to employment and experienced financial hardships in day-to-day life [44]. It was evident that financial/employment-related issues substantially contribute to 13% of suicide deaths [45]. On the other hand, job loss or financial hardships independently lead to significant and persistent increases in domestic violence [46]. Similarly, social isolation and stay-at-home rules imposed by many counties badly resulted in domestic violence, making survivors of domestic violence at risk for further violence and isolating them from networks of support [47]. Furthermore, it is evident that during pandemics, a considerable number of people present with anxiety and depressive symptoms though they do not have any pre-existing mental health conditions [8]. As a result of this, some experience post-traumatic stress disorders in due course of their lives, which can end up with suicidal attempts or deaths. Nonetheless, a delayed increase in suicide rates is possible following major disasters [48,49,50]. Therefore, preventing suicidal attempts and deaths in the context of COVID 19 is a critical public health priority.

Considering the importance of preventing suicidal attempts and deaths secondary to the COVID 19 pandemic, early detection and timely intervention for individuals with suicidal behaviors is crucial [51]. Unlike previous pandemics, COVID-19 is occurring in the modern digital world, where video conferencing and virtual healthcare provision are widely available [52]. Although some people experience suicidal ideas during this pandemic, they might not attempt to seek help because of fear that meeting a health care professional face-to-face might put them at risk of contacting COVID-19. In this regard, as several studies have already identified the positive effects of new technologies in combating and preventing suicidal behavior, virtual platforms can be used as an effective way of screening to identify the people those at risk at the early stages [51, 53]. To strengthen this approach, community-based training programs can be used periodically to approach the neediest people early. Moreover, media should also be responsible when reporting facts, avoiding stoking fear and hopelessness among people in the community [18]. Therefore, it is recommended to use the recommendations given by this review to prevent suicidal attempts or suicidal deaths during the COVID-19 pandemic.

There are a few limitations in this review. The findings of this review can be limited because of not including the potential articles beyond the search strategies. Besides, the studies included in this review used different durations for data collection during the COVID 19 pandemic making it difficult to estimate the incidence rate of suicidal attempts and deaths only for the COVID 19 pandemic. Moreover, the inter-rater agreement was not calculated for this review as the screening process was undertaken in Covidence systematic review manager software. Despite these limitations, this review provides; (i) the first observation of suicidal attempts and suicidal deaths during the COVID-19 pandemic, (ii) the risk factors for suicidal attempts and suicidal deaths during the COVID-19 pandemic, and (iii) the recommendations in preventing suicidal attempts or suicidal deaths during the COVID-19 pandemic. Suicide prevention in the COVID-19 era and similar pandemics are crucial and challenging. Therefore, it is essential to select appropriate suicide prevention strategies based on strong evidence. The findings of this study can be used when selecting appropriate suicide prevention strategies considering the identified risk factors and recommendations given. It is recommended to discuss the longitudinal trends in future studies.