The impact of the COVID-19 pandemic on self-harm and suicidal behaviour: update of living systematic review

Background: The COVID-19 pandemic has caused considerable morbidity, mortality and disruption to people’s lives around the world. There are concerns that rates of suicide and suicidal behaviour may rise during and in its aftermath. Our living systematic review synthesises findings from emerging literature on incidence and prevalence of suicidal behaviour as well as suicide prevention efforts in relation to COVID-19, with this iteration synthesising relevant evidence up to 19 th October 2020. Method: Automated daily searches feed into a web-based database with screening and data extraction functionalities. Eligibility criteria include incidence/prevalence of suicidal behaviour, exposure-outcome relationships and effects of interventions in relation to the COVID-19 pandemic. Outcomes of interest are suicide, self-harm or attempted suicide and suicidal thoughts. No restrictions are placed on language or study type, except for single-person case reports. We exclude one-off cross-sectional studies without either pre-pandemic measures or comparisons of COVID-19 positive vs. unaffected individuals. Results: Searches identified 6,226 articles. Seventy-eight articles met our inclusion criteria. We identified a further 64 relevant cross-sectional studies that did not meet our revised inclusion criteria. Thirty-four articles were not peer-reviewed (e.g. research letters, pre-prints). All articles were based on observational studies. There was no consistent evidence of a rise in suicide but many studies noted adverse economic effects were evolving. There was evidence of a rise in community distress, fall in hospital presentation for suicidal behaviour and early evidence of an increased frequency of suicidal thoughts in those who had become infected with COVID-19. Conclusions: Research evidence of the impact of COVID-19 on suicidal behaviour is accumulating rapidly. This living review provides a regular synthesis of the most up-to-date research evidence to guide public health and clinical policy to mitigate the impact of COVID-19 on suicide risk as the longer term impacts of the pandemic on suicide risk are researched.

prevalence of suicidal behaviour as well as suicide prevention efforts in relation to , with this iteration synthesising relevant evidence up to 19 th October 2020. Method: Automated daily searches feed into a web-based database with screening and data extraction functionalities. Eligibility criteria include incidence/prevalence of suicidal behaviour, exposure-outcome relationships and effects of interventions in relation to the COVID-19 pandemic. Outcomes of interest are suicide, self-harm or attempted suicide and suicidal thoughts. No restrictions are placed on language or study type, except for single-person case reports. We exclude oneoff cross-sectional studies without either pre-pandemic measures or comparisons of COVID-19 positive vs. unaffected individuals. Results: Searches identified 6,226 articles. Seventy-eight articles met our inclusion criteria. We identified a further 64 relevant crosssectional studies that did not meet our revised inclusion criteria. Thirty-four articles were not peer-reviewed (e.g. research letters, preprints). All articles were based on observational studies. There was no consistent evidence of a rise in suicide but many studies noted adverse economic effects were evolving. There was evidence of a rise in community distress, fall in hospital presentation for suicidal behaviour and early evidence of an increased frequency of suicidal thoughts in those who had become infected with COVID-19. Conclusions: Research evidence of the impact of COVID-19 on suicidal behaviour is accumulating rapidly. This living review provides a regular synthesis of the most up-to-date research evidence to guide public health and clinical policy to mitigate the impact of COVID-19 on suicide risk as the longer term impacts of the pandemic on suicide risk are researched.

Keywords
COVID-19, Living systematic review, Suicide; Attempted suicide, Selfharm, Suicidal thoughts This article is included in the Disease Outbreaks gateway.
This article is included in the Living Evidence collection. 04 Sep 2020 report report report

Introduction
The COVID-19 pandemic is causing widespread societal disruption, morbidity and loss of life globally. By the end of December 2020 over 85 million people had been infected and over 1.8 million had died (Worldometers, 2020). There are concerns about the impact of the pandemic on population mental health (Holmes et al., 2020). These stem from the impact of the virus itself on people infected (Taquet et al., 2021), as well as frontline workers caring for them (Kisely et al., 2020) and increases in bereavement. Other concerns relate to the impact on population mental health of the public health measures that have been implemented to minimise the spread of the virus -in particular physical distancing, leading to social isolation, disruption of businesses, services and education and threats to peoples' livelihoods. Physical distancing measures and lockdowns have resulted in substantial rises in unemployment, falls in GDP and concerns that many nations will enter a prolonged period of deep economic recession.
There are concerns that suicide and self-harm rates may rise during and in the aftermath of the pandemic (Gunnell et al., 2020;Reger et al., 2020). Time-series modelling indicated that the 1918-20 Spanish Flu pandemic, which caused well over 20 million deaths worldwide, led to a modest rise in the national suicide rate in the USA (Wasserman, 1992) and Taiwan (Chang et al., 2020). Likewise, there is some evidence that previous epidemics and pandemics were associated with rises in suicide and suicidal behaviour (Zortea et al., 2020). Suicide rates increased briefly amongst people aged over 65 years in Hong Kong during the 2003 SARS epidemic, predominantly amongst those with more severe physical illness and physical dependency (Cheung et al., 2008).
The current context is, however, very different from previous epidemics and pandemics. The 2003 SARS epidemic was restricted to relatively few countries. Furthermore, during the 100-year period since the 1918-20 influenza pandemic, global and national health systems have improved, international travel and the speed of communication of information (and disinformation) have increased, antibiotics are available to treat secondary infection, and national economies have become globally inter-dependent. The availability of the internet and technological advancement has made it far easier for people to communicate and engage in home working and home schooling. However, there are marked social inequalities in relation to access to technology and ability to stay safe and continue to work, within and between countries. Public health policies and responses, and the degree of access to technology to facilitate online clinical assessments and treatments differ greatly between countries.
Key concerns in relation to suicide prevention during the pandemic include: encouraging help-seeking in those with suicidal thoughts and behaviours e.g. people who have attempted suicide may not attend hospitals because they are worried about contracting COVID-19 or being a burden on the healthcare system at this time; uncertainty regarding how best to assess and support people with suicidal thoughts and behaviours, whilst maintaining physical distancing and addressing any impacts of remote consultation; diminished access to community-based support; exposure to traumatic experiences; long term effect of infection with the virus on mental health (Taquet et al., 2021) and an economic recession may have an adverse impact on suicide rates (Chang et al., 2013;Stuckler et al., 2009). There have been increases in bereavement (with many being unusually complicated during the crisis), sales of alcohol (Finlay & Gilmore, 2020) and domestic violence (Mahase, 2020) -all risk factors for suicide (Turecki et al., 2019); the insensitive or irresponsible media reporting of suicide deaths associated with COVID-19 may be harmful (Hawton et al., 2021); and in some countries access to highly lethal suicide methods such as firearms and pesticides may rise (Anestis et al., 2021;Gunnell et al., 2020). However early findings from high income countries with 'real-time' suicide trend data, indicates there was no rise in suicide rates in the early months of the pandemic (John et al., 2020a). Japan is the exception to this rule, falls in Japanese suicide rates in the early months of the pandemic have since been replaced by rises above pre-pandemic levels July/ August 2020 and beyond (John et al., 2020a;Tanaka & Okamoto, 2021;Ueda et al., 2021). The longer-term impact of the pandemic on suicide deaths and suicidal behaviour remains uncertain.
In the context of the COVID-19 pandemic there is a rapidly expanding evidence base on its impact on suicide rates, and how best to mitigate such effects. It is therefore important that the best available knowledge is made rapidly available to

Amendments from Version 1
This update of our living systematic reviews includes literature up to October 2020 whereas our last was up to 7th June 2020. Searches identified 6,226 articles. Seventy-eight articles met our revised inclusion criteria, 49 more than in our previous review. All were still based on observational studies. The majority of studies remained case series but there are now an increased number of service utilisation studies from across the world. There were still no studies were based on populations from sub-saharan Africa.
In contrast to the last update in which no studies reported on the change in incidence of suicide or suicidal behaviour after the onset of the pandemic compared with beforehand, we identified nine papers in this update, presenting data on studies from four countries which investigated the impact of COVID-19 on suicide rates. To date, the highest quality data come from Japan which utilises suicide records covering the entire population; these data indicate that the impact of COVID-19 on suicides rates may change over time and have varying effects on different sections of the population. There was no consistent evidence of a rise in suicide but many studies noted adverse economic effects were evolving. There was evidence of a rise in community distress, fall in hospital presentation for suicidal behaviour and early evidence of an increased frequency of suicidal thoughts in those who had become infected with COVID-19. We have updated the author order to reflect contribution to this update, predominately related to oversight of specific tables and drafting specific sections of text. We have added new authors who have joined the screening team.
Any further responses from the reviewers can be found at the end of the article REVISED policymakers, public health specialists and clinicians. To facilitate this, we are conducting a living systematic review focusing on incidence and prevention of suicide and self-harm in relation to COVID-19. Living systematic reviews are high-quality, up-to-date online summaries of research that are regularly updated, using efficient, often semi-automated, systems of production (Elliott et al., 2014). Our first report covered the period up to the 7 th June 2020. This paper reports the second set of findings from the review, based on relevant articles identified up to 19 th October 2020.

Aim
The overarching aim of the review is to identify and appraise any newly published evidence from around the world that assesses the impact of the COVID-19 pandemic on suicide deaths, suicidal behaviours, self-harm and suicidal thoughts, or that assesses the effectiveness of strategies to reduce the risk of suicide deaths, suicidal behaviours, self-harm and suicidal thoughts, associated with the COVID-19 pandemic.

Methods
This living systematic review ( Figure 1) follows published guidance for such reviews and for how expedited 'living' recommendations should be formulated where relevant (Akl et al., 2017;Elliott et al., 2017). The review was prospectively registered (PROSPERO ID CRD42020183326; registered on 1 st May 2020). An overview of our living review process is provided in Figure 1. A protocol (John et al., 2020b) was published in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols guideline (Moher et al., 2015) along with the first update of our review which summarised articles identified up to 7 th June 2020 (John et al., 2020c). Since publication of our protocol we have amended our methodology to: 1) search additionally the PsyArXiv Figure 1. Workflow for updating the living systematic review review. The process will be supported using automation technology and at three-monthly intervals the team will update the published version of the review. and SocArXiv open access paper repositories; 2) include modelling studies within the scope of our review (e.g. to predict the likely impact of the pandemic on suicide rates); 3) update our research questions to include studying the impact of adult self-neglect and parental neglect and fear of losing livelihood on suicide-related outcomes; 4) update our searches with any new citations from PsycINFO prior to each update; 5) exclude from data extraction and presentation in results tables single-wave, cross-sectional surveys unless they explicitly make comparisons with appropriate pre-pandemic measures or include comparative data between COVID-19 positive and unaffected individuals for pragmatic reasons, due to the volume of such studes but also issues to do with sampling and generalisability of such studies. Surveys that meet the original inclusion criteria are included as an appendix to the update.

Eligibility criteria
Study participants may be adults or children of any ethnicities living in any country. Outcomes of interest are: 1. Deaths by suicide 2. Self-harm (intentional self-injury or self-poisoning regardless of motivation and intent) or attempted suicide (including hospital attendance and/or admission for these reasons)

Suicidal thoughts/ideation
Studies must address one of the following research questions: (i) What is the prevalence/incidence? • Impact of any other relevant exposure on our outcomes of interest.

Qualitative research
We included any qualitative research addressing perceptions or experiences around each outcome in relation to the COVID-19 pandemic (e.g. stigma of infection, isolation measures, complicated bereavement, media reporting, experience of delivering or receiving remote methods of self-harm / suicide risk assessment or provision of treatment; experience of seeking help for individuals in suicidal crisis); narratives provided for precipitating factors for each outcome.
No restrictions were placed on the types of study design eligible for inclusion, except for the exclusion of single-person case reports. Pre-prints will be re-assessed at the time of publication and the most current version included. There was no restriction on language of publication. We drew on a combination of internet-based translation systems and network of colleagues to translate reports in languages other than English.

Identification of eligible studies
We searched the following electronic databases: PubMed; Scopus; medRxiv, PsyArXiv; SocArXiv; bioRxiv; the COVID-19 Open Research Dataset (CORD-19) by Semantic Scholar and the Allen Institute for AI, which includes relevant records from Microsoft Academic, Elsevier, arXiv and PMC; and the WHO COVID-19 database. A sample search strategy (for PubMed) appears in Box 1 from 1 st January 2020 to 19 th October 2020. We have developed a workflow that automates daily searches of these databases, and the code supporting this process can be found at https://github.com/mcguinlu/COVID_suicide_living). Searches are conducted daily via PubMed and Scopus application programme interface and the bioRxiv and medRxiv RSS feeds. Conversion scripts for the daily updated WHO and the weekly updated CORD-19 corpus are used to collect information from the remaining sources. The software includes a systematic search function based on regular expressions to search results retrieved from the WHO, CORD-19 and preprint repositories (search strategy available in extended data). Our review is ongoing and we continue to investigate the use of other databases and to capture articles made available prior to peer review and assess eligibility and review internally. For this update we therefore included PsyArXiv and SocArXiv repositories in our search strategy via their own open access platforms as we developed our automated system. PsycINFO searches were carried out retrospectively on 6 th January 2021, using a publication date filter for 1 st January 2020 to 19 th October 2020.
A two-stage screening process was undertaken to identify studies meeting the eligibility criteria. First, two authors (either CO or EE) assessed citations from the searches and identified potentially relevant titles and abstracts. Second, either DG, AJ or RW assessed the full texts of potentially eligible studies to identify studies to be included in the review. This process was managed via a custom-built online platform (Shiny web app, supported by a MongoDB database). The platform allowed for data extraction via a built-in form.

Data collection and assessment of risk of bias
One author (DG, AJ or RW) extracted data from each included study using a piloted data extraction form, and the extracted data were checked by one other author (DG, KH, EA, RC, AJ, or EE where AJ extracted data, AJ where DG extracted data). Disagreements were resolved through discussion, and where this failed, by referral to a third reviewer (KH, NK or PM). Irrespective of study design, data source and outcome measure examined, the following basic information were extracted: citation; study aims and objectives; country/setting; characteristics of participants; methods; outcome measures (related to self-harm / suicidal behaviour and COVID-19); key findings; strengths and limitations; reviewer's notes. For articles where causal inferences are made -i.e. randomised or non-randomised studies examining the effects of interventions or aetiological epidemiological studies of the effects of specific exposures -we plan to use a suitable version of the ROBINS-I or a preliminary similar tool for exposure studies to assess risk of bias as appropriate based on the research question and study design (Morgan et al., 2017;Sterne et al., 2016).

Data synthesis
We synthesised studies according to themes based on research questions and study design, using tables and narrative. Results were synthesised separately for studies in the general population, in health and social care staff and other at-risk occupations, and in vulnerable populations (e.g. people of older age or those with underlying conditions that predispose them to becoming severely ill or dying after contracting COVID-19) where relevant. Where multiple studies addressed the same research questions, we assessed whether meta-analysis was appropriate and would conduct it where suitable, following standard guidance available in the Cochrane Handbook (Deeks et al., 2019). The current document is the second iteration of our review. We have not considered it appropriate to combine any results identified so far in a meta-analysis due to quality and heterogeneity.

Results
In total, 12,397 citations were identified by 19 th October 2020 from all electronic searches, after duplicates were removed ( Figure 2). The cumulative numbers of articles over time that were identified by the search and included in the review are shown in Figure 3 and Figure 4. The majority of studies identified in the review (5105; 82%) were sourced from two databases, PubMed and WHO; a further 10% (n=622) were drawn from pre-print sites such as MedRxiv.

Description of included studies
We included 78 articles in the review. We have highlighted in Table 1- Table 6 where new citations have updated existing studies. Sixty-four cross sectional surveys are included in Appendix 1. In total, six studies spanned several countries or were worldwide, including one using a Reddit mental health dataset (almost half of users are from the USA); 13 were from the United States; seven from China; nine from India; five from the United Kingdom; four each from Japan and Nepal; and between one and three each from Australia, Bangladesh, Canada, Czech Republic, Denmark, France, Germany, Greece, Iran, Ireland, Israel, Italy, Pakistan, Peru, Poland, Portugal, Spain, Qatar and Switzerland. All articles were based on observational studies: twenty-five were case series with a sample of two or more (although Jefson et al., 2020 andRohde et al., 2020 were based on the same case series); thirteen were cross sectional surveys; two were based on social media posts; six were modelling studies; twenty were service utilisation studies; and nine assessed suicide rates. Studies are summarised by these study types in Table 1 through Table 6. Three other relevant articles were identified, two of these described mixed methods studies (Evans et al., 2020;Son et al., 2020) and one a casecontrol study (Cai et al., 2020). Almost half (n=34) of the articles did not appear to have been peer-reviewed of which ten were pre-prints and 21 were published as research letters to the Editor.

Study populations
Sample sizes ranged from two individuals in a number of case series (Kapilan, 2020;Mamun et al., 2020b;Pirnia et al., 2020;Sahoo et al., 2020) to 60 million Twitter posts (Saha et al., 2020). Most studies included both male and female participants, except the studies reported by Wu et al. (2020a) and Sade et al.
(2020) which were conducted in pregnant women.

Outcomes
Seven of the 24 case series (described in 25 papers) focused on a mix of outcomes including suicide attempts (n=2), suicide deaths (n=14) and suicidal thoughts (n=1). Of the 15 crosssectional surveys five assessed suicidal thoughts alone, others collected data on various combinations of suicidal/self-harming behaviour or thoughts. A range of validated questionnairres were used to assess suicidal thoughts ( Table 2). Five surveys used the single item from PHQ-9 'Have you had thoughts that you would be better off dead or of hurting yourself in some way' over the last 2 weeks. Wang et al. (2020b)    Suicide death AWS seems implicated in a number of suicides in southern India but, on the basis of the empirical information that is presented here, we do not know whether these deaths were caused by the COVID-19 lockdown, and whether these deaths occurred at a higher frequency during the observation period than they normally occur.
We cannot be sure whether any of the suicides occurred primarily as a direct consequence of AWS, or were brought about due to the unavailability of alcohol during lockdown. Study uses news reports as their data source.
Letter to the editor, so unlikely to be peer reviewed. Suicide attempt and/or death (couples) Details several potential reasons:

1) Fear of infection;
2) Money problems (due to recession associated with lockdowns); 3) Harassment or victimisation by others due to (possibly perceived) infection status; 4) Stress of being in isolation or quarantine; and 5) Uncertainty of when the pandemic will end.
Small sample size (n=6) Study uses news reports as their data source.
Letter to editor, probably not peer reviewed.
Suicide death 7 Indian film stars who died by suicide. Media reports claimed three of these were related to financial problems associated with COVID-19. It is unclear whether any of the deaths were strongly linked with COVID-19 and its indirect impact on people's lives, or whether the individuals were already experiencing mental health difficulties.
Study uses news reports as their data source.
Appears to use the same data as Mamun et al., 2020b. Letter to the editor; probably not peer reviewed.

Mamun et al., 2020a
Bangladesh News report of suicide pact in mother and 22 year old son, 11 Jun 2020 (n=2) Suicide death University student aged 22 and his mother aged 47 died by suicide. The father had insisted the day before that the student complete online exams as an internet connection was arranged.
Study uses news reports as their data source.
Only a single pact reported Suggests that online teaching in LMIC may create real tensions due to digital poverty Letter to the editor; possibly not peer reviewed.

Suicide death
The frequency of celebrity suicides in India appears to have increased markedly during the COVID-19 era.
The authors highlight the dangers of sensationalised media reporting of celebrity suicides triggering immitative events in the general population.
Study uses news reports as their data source.
Appears to use the same data as Kar et al., 2020 Letter to the editor; possibly not peer reviewed.

Mamun & Ullah, 2020
Pakistan News reports of COVID-19 related suicide deaths in Pakistan, Jan 2020 to end April 2020 (n=12, a further 4 reports of suspected suicide were not presented).

Suicide death
Economic concerns reported in 8/12 cases, and fear of infection in the remaining 4.
There were 13 other reports of suicides (and attempted suicide) during this period not reported to be linked to COVID-19.
Highlights the potential importance of the economic impact of COVID-19 and/or public health measures on influencing suicide in low-and middle-income countries.
Study uses news reports as their data source. Peer reviewed journal; paper accepted on same day as received. No pre-illness baseline measure. Used PHQ-9 (standardised measure). Letter to editor, probably not peer reviewed.
Scenario b) associated with a 3.3% rise in suicide in 2020-21 Scenario c) associated with an 8.4% rise in suicide in 2020-21.
Usefully models the potential impact of two different unemployment rate rises.
No account for potential impacts of pandemic other than via unemployment rises Duration of unemployment rises uncertain

Peer reviewed
Authors Country / region Data used to inform estimate
Scenario b) associated with a 5.5% rise in suicide in 2020-21 Scenario c) associated with a 27.7% rise in suicide in 2020-21.
Usefully models the potential impact of two different unemployment rate rises.
No account for potential impacts of pandemic other than via unemployment rises Duration of unemployment rises uncertain The team modelled the impact of COVID-19 pandemic on multiple outcomes as well as suicide.
Prison confinement is probably not a good proxy for effects of lockdown. High suicide rates in prisoners are due to multiple factors e.g. age and gender profile; high levels of psychiatric morbidity rather than impacts of confinement.
Other potential factors e.g. rises in unemployment not included in models Pre-print, not peer reviewed. August 2020. Data also presented for suicidal thoughts, but data were combined with "low mood" Intentional drug overdose and self-harm A marked reduction (p<0.001) in liaison psychiatry referrals for intentional drug overdose, self-harm and suicidal thoughts occurred after 23 March (lockdown).
The proportion of referrals returned to pre-lockdown levels by May/June 2020.
Liaison team referral only (not all ED attendances) at a single hospital. Analysis did not account for possible underlying temporal trends in suicide using time-series approaches.
Publicly available national statistics. Possibly too short a timespan to assess impact on child suicides. Suicides among children and adolescents reportedly peak at the beginning of school semesters in Japan, suicide rates may have increased when school restarted in June 2020. July 2016 -June 2020 Compared Use Feb-Jun 2020 (COVID period) vs. and Feb-Jun 2016-19 (pre-COVID). Suicides fell by 13.5% (95% CI -17.5 to -9.5%) in the COVID period. Decline is greatest in males and in adults compared to children (<20 years) and older people (>70 years). No evidence of an adverse effect on students during school closure (rates fell).
Publicly available national statistics. The authors cite the Japanese government's "generous subsidies, reduced working hours, and fewer school sessions" as possible explanations for lack of adverse effect. Pre-print. Not peer reviewed.

Ueda et al., 2021
Japan Suicide statistics (all ages) published by the Ministry of Health, Labor and Welfare.
By August suicide numbers were 7.7% higher than the average for August 2016-19. The largest rises were in females (mean of 532 suicides in August 2017-19 vs. 651 in 2020). Similar trajectories in all age groups, but the largest rise was in those aged <40 years (63% higher in 2020 vs 2017-19).
Groups of greatest concern: students (47% rise in university student suicides August 2020 vs August 2017-19) and housekeepers.
Authors speculate greater rise in women could be because they largely worked in the sectors most affected by pandemic related closure (retail and travel) The analysis did not account for possible underlying temporal trends in suicide using time-series approaches.
the authors compare the percentage change in a single month in 2020 vs figures for the same month in 2017-19. Pre-print. Not peer reviewed assessed responses to this question in a symptom network analysis.
Many reasons for COVID-19 related suicide or suicide attempts were suggested in the case series with conclusions often derived from a journalist's report of the death. Contributory factors reported included fear of contracting the disease or of passing it on to others, reactive psychoses, financial or economic issues, loneliness and isolation due to quarantine, stress among health professionals, the uncertainty around when the pandemic would end, misinterpretation of fever as COVID-19, contracting COVID-19, an inability for migrants to return home, frustration and the stigma of a (possibly perceived) positive result, which resulted in harassment or victimisation by others in the community. In the largest case series from India (n=72 suicide deaths), Dsouza et al. (2020) reported that the most commonly occurring antecedents to suicide were fear of infection (n=21) and financial crisis (n=19). Two studies reported specifically on the consequences of alcohol withdrawal due to lockdowns (Ahmed et al., 2020;Syed et al., 2020).
In the USA, four case reports described stressors for adolescents which include inability to see friends, arguments with parents, unresolvable misunderstandings over social media, academic stress, and feelings of isolation (Jolly et al., 2020). In a case series of adults across three hospitals in Doha, Qatar, three patients (out of 50 patients with COVID-19 receiving a psychiatric diagnosis) self-harmed as a reaction to the pandemic (Iqbal et al., 2020). A study of TriNetX records of people with 469) found that 0.2% (62 individuals) had suicidal thoughts recorded, although clinicians may not have systematically asked about suicidality (Nalleballe et al., 2020).
Summary of study findings: Cross-sectional surveys and cohort study There were 13 articles describing cross-sectional surveys / cohort studies of two or more waves or one wave surveys where comparisons were explicitly made with appropriate pre-pandemic measures; or included comparative data between COVID-19 positive individuals and unaffected comparison individuals ( Table 2). Six studies present repeat survey data, with measures recorded during, as well as before, the pandemic (Hamm et al., 2020;Hamza et al., 2021;Raifman et al., 2020;Winkler et al., 2020;Wu et al., 2020b;Zhang et al., 2020). Raifman et al. (2020) compared two nationally representative samples of US adults (one from 2017/18 and one from 2020 during the COVID-19 pandemic) using different survey methodologies. They found that suicidal ideation had increased more than fourfold in low-income households, particularly in those with difficulty paying rent, job loss and loneliness. Similarly, Winkler et al. (2020) reported on a repeated, robustly-sampled, nationally representative survey in the Czech Republic using baseline data from 2017 and found that suicide risk, as measured by the Mini International Neuropsychiatric Interview, increased from 3.9% in November 2017 to 11.9% in May 2020. Both In a general population sample that included people who reported having been diagnosed with COVID-19, Iob et al. (2020) found suicide/self-harm thoughts were more common in those with a COVID-19 diagnosis than in those not affected (33% vs 17%); likewise for suicide attempts (14% vs. 5%). Two surveys were conducted in university student populations (Debowska et al., 2020;Hamza et al., 2021) from 11 universities, with predominantly female respondents. No statistical evidence of a rise in suicidal thoughts or self-injury was found over a number of waves of data collection. Surveys were targeted at specific populations in a further three studies ( Table 2)

Summary of study findings: Social media platform posts
Two studies (Table 3)
The models suggest between a 1% rise (Kawohl & Nordt, 2020, globally) and a 145% rise (Moser et al., 2020, in Switzerland) in suicide deaths. Each was based on different assumptions, but the models largely focused on the well-characterised impact on suicide rates of periods of economic recession and rises in unemployment (Chang et al., 2013;Stuckler et al., 2009). Unemployment rates are predicted to rise as a result of a postpandemic recession, due to measures to control the spread of the virus on the wider economy and loss of work as many businesses have been forced to shut down.
Only one study modelled the effects of physical distancing measures on suicide rates (Moser et al., 2020); it did this by using suicide rates in prisoners in group or single cells as a model for lockdown in a group or in isolation. The prison population is exposed to multiple other risk factors for suicide (e.g. increased prevalence of mental illness, substance misuse and low socioeconomic position) (Humber et al., 2011;Rivlin et al., 2010), and this, coupled with the distinct differences between prison incarceration and the adoption of home quarantine procedures during the pandemic, means this model is likely to overestimate the potential impact of physical distancing measures on suicide risk in the general population.

Summary of studies' findings: Service utilisation studies
We identified 20 service utilisation studies. Four of these addressed the impact of COVID-19 on suicidal thoughts only, thirteen included suicide attempts and/or self-harm, one suicidal thoughts, attempts and self-harm (McAndrew et al., 2020), one suicide threats and suicides in progress (Lersch, 2020), while in one the precise nature of the suicidal outcome was unclear (Sheridan et al., 2021) ( Table 5). Most studies were conducted in the US (5) and the UK (4), three in Australia, two in Ireland and one study in each of the following countries: France, Greece, Israel, Italy, Portugal, and Spain.
Across the studies focusing on suicidal thoughts, the methodologies varied from studies of presentations to health/mental health services to callers/visits to a website, with wide-ranging sample sizes, from 1668(Titov et al., 2020 to 90 (Sade et al., 2020); the latter including a specific sample of pregnant women.
The studies showed either a reduction (Chen et al., 2020;Hernandez-Calle et al., 2020;Smalley et al., 2021) or no change (Sade et al., 2020;Titov et al., 2020) in presentations to health/ mental health services or self-reported suicidal thoughts, with the majority making comparisons to the same time in 2019. The eleven studies examining the impact of COVID-19 on self-harm/suicide attempts used a variety of methodologies, including accessing data from health/mental health services, trauma registries, community-based services, emergency call services and the prison service. Where reported, the sample sizes ranged from 18, 646 (Walker et al., 2020) to 30 (Olding et al., 2021). Eight studies reported a decrease in self-harm/suicide attempts during the first months of the COVID-19 pandemic (Capuzzi et al., 2020;Chen et al., 2020;Goncalves-Pinho et al., 2021;Hewson et al., 2020;McIntyre et al., 2020;Pignon et al., 2020;Rajput et al., 2020;Walker et al., 2020). however presentations returned to pre-pandemic levels by the end of May. Another study in Ireland (Mcandrew et al., 2020) also reported a reduction in psychiatric emergency presentations to the emergency department but no change in the proportion of presentations with suicidal thoughts or self-harm. In a study conducted by Hewson et al. (2020) in 31 prisons in the UK between February and April 2020, self-harm incidents decreased by one third between February and April 2020.
In contrast, whilst Olding et al. (2021) reported a reduction in the incidence of all types of penetrating trauma presenting to a UK hospital during the early period of lockdown, the number of self-harm presentations increased slightly (albeit on the basis of very low event counts). A similar pattern was identified by Karakasi et al. (2020a) in Greece, where between March and May 2020 a significant reduction was observed in individuals presenting as emergencies at hospital for psychiatric examination (the number of presentations for suicide attempts was 7 compared with 5 in the same period in 2019). Capuzzi et al. (2020) reported a rise in self-harm / suicide attempts as a proportion of total emergency department presentations in Italy, but this rise in the proportion of cases was in the context of falls in the absolute numbers of cases, set against reductions in total emergency department attendances.
A study of emergency police calls in Detroit, USA, (Lersch et al., 2020) showed that the number of general mental health calls declined after the onset of the pandemic in that city, while calls relating to suicides in progress remained relatively stable over the 4 year period. Calls involving suicide threats declined inversely to the increase in COVID-19 infections, although the authors noted some 'hotspots' within the city for both infection rates and suicide threats. A study of 31 prisons in the UK found that after lockdown there were fewer implementations of Assessment, Care in Custody and Teamwork (ACCT) processes to initiate care-plans for prisoners considered at risk of self-harm or suicide (Hewson et al., 2020).
Summary of study findings: impact of COVID-19 on suicide rates Nine reports, based on data from four countries -Greece, Japan, Nepal and Peru -describe changes in suicide rates in relation to the onset of COVID-19 and national lockdowns.
A challenge with interpreting all the reports is the uncertainty over the extent to which official recording of suicides may have been affected by disruptions in death investigation and reporting due to COVID-19, although this is more likely to lead to under-estimation than over-estimation of suicide rates.
Only one of the studies (Calderon-Anyosa & Kaufman, 2020) used appropriate time series to take account of underlying temporal trends in suicide when comparing the COVID-19 period with earlier years/months.
The four reports from Nepal (Acharya et al., 2020;Pokhrel et al., 2021;Poudel & Sedhai, 2020;Singh et al., 2020) were all based on news reports of police data on suicides, rather than on data obtained directly from Nepalese authorities and did not describe the strengths and weakness of the police data. They report between a 20% (Poudel & Sedhai, 2020) and 35% (Acharya et al., 2020) rise in suicide in the first 3 months after lockdown compared with either preceding months or a similar period the previous year. These are marked rises, but without longer time series data it is not possible to determine the extent to which these were COVID-19 related or a possible continuation of pre-existing adverse trends. Three reports, based on Japan's timely national suicide statistics, describe recent trends in Japanese suicide rates (Tanaka & Okamoto, 2020pre-print, Tanaka & Okamoto, 2021Isumi et al., 2020;Ueda et al., 2021). The most recent of these, using data up to October 2020, indicate that 14% falls in Japanese suicides in the early months of the pandemic (Feb-June 2020), were reversed during the second outbreak (July to October, 2020) increasing by 16% (Tanaka & Okamoto, 2021). Increases in suicide rates were higher in females (especially housewives) and children and adolescents. Similarly compared with August in 2017-19, figures for August 2020 were increased by 7.7%, with rises particularly in females and people aged <40 years (Ueda et al., 2021). An early report (data up to May 2020) provided some reassurance about the impact of public health measures/ school closures on suicide rates in children (<20 years) in Japan (Isumi et al., 2020). However, more recent data (Ueda et al., 2021) flags a concerning rise amongst students and young (<40 years) people, particularly females. The numbers of deaths in the autopsy study from Athens (Sakelliadis et al., 2020) is too small to reach any conclusion about the impact on suicide in Greece. Calderon-Anyosa's (2020) study of suicide in Peru is reassuring, though details of potential impacts of COVID-19 on death registration in Peru are not provided.

Other studies
The three other studies investigated various risk groups, using case control and mixed methods approaches. Son et al.
(2020) interviewed students from a single US university about the impacts of the pandemic on their mental health; some students described suicidal thoughts and the challenges they faced, one linked suicidal thoughts to being confined at home with their family and another to study-related difficulties. Cai et al. (2020) compared suicidal thoughts in Chinese medical workers dealing with COVID-19 patients and those not in contact with such patients. They found no evidence of increased levels of suicidal thoughts amongst those in contact with COVID patients. Lastly, Evans et al. (2020) studied the pandemicrelated stresses felt by Australian families in free text responses to a questionnaire. One respondent, a father with three children described the extreme financial distress they faced with "our three businesses closing, we are eligible for none of the government support due to a tax debt and are looking at bankruptcy and selling our home as the only option. Both of us have had thoughts of suicide" (Quote from father of 3 children). (Evans et al., 2020)

Discussion
Seventy-eight articles were included in this review, 49 more than in our review of studies published up to 7 th June 2020. All were based on observational studies. The majority of studies were case series or service utilisation studies from across the world. No studies were based on populations from sub-saharan Africa. Almost half of the articles did not appear to have been peer-reviewed, consisting mainly of pre-prints published before peer review, or research letters that may not have been peer-reviewed. In contrast to the last update (John et al., 2020c) in which no studies reported on the change in incidence of suicide or suicidal behaviour after the onset of the pandemic compared with beforehand, we identified nine papers in this update, presenting data on studies from four countries which investigated the impact of COVID-19 on suicide rates. To date, the highest quality data come from Japan which utilises suicide records covering the entire population; these data indicate that the impact of COVID-19 on suicides rates may change over time and have varying effects on different sections of the population. Analysis of data from Peru used appropriate analytic techniques and reported a fall in suicides following the onset of the pandemic during the months March to September (Calderon-Anyosa & Kaufman, 2020). Methodological limitations and the availability of data for only four countries limit our ability to assess the early impact of COVID-19 on suicide rates in this update.
Evidence published following our cut-off date for inclusion in this iteration of the review indicates there was no rise in suicide rates in the early months of the pandemic in high income countries (John et al., 2020a). Since our 19 th October search, a further 13 studies analysing suicide trends in ten countries or regions within countries (Australia, Austria, Germany, Greece, Japan; Korea, Norway, Sweden, Thailand and the USA) have been published (Ando & Furuichi, 2020;Bray et al., 2021: Deisenhammer & Kemmler, 2021Faust et al., 2020;Karakasi et al., 2021;Ketphan et al., 2020;Kim, 2021;Leske et al., 2021;Mitchell & Li, 2021;Qin & Mehlum, 2021;Radeloff et al., 2020 andRadeloff et al., 2021;Rück et al., 2020;Vandoros et al., 2020). Four of these use appropriate time-series modelling approaches to control for underlying trends (Leske et al., 2021, Australia;Faust et al., 2020, USA;Vandoros et al., 2020, Greece;Ando et al., 2020, Japan) -these report either no change or a fall in suicide deaths in the early months of the pandemic, although in keeping with Tanaka & Okamoto (2020); Tanaka & Okamoto (2021) and Ueda et al.'s (2021) analysis for Japan, Ando et al. (2020) report a rise in suicides in Japan since July associated with increased unemployment .
In keeping with concerns from Nepal, data from Thailand's Department of Mental Health indicate suicide numbers have risen during the pandemic (Ketphan et al., 2020). Data from Connecticut, USA on suicides during the 10 weeks of stringent lockdown measures in the state indicate that whilst suicide rates fell during this period, the proportion of suicides amongst minority ethnic groups rose, highlighting the possibility that the pandemic may be having a disproportionately greater adverse impact on minority groups (Mitchell & Li., 2021). A concern supported by a recent analysis from Maryland, USA. (Bray et al., 2021).
The majority of the 13 included cross-sectional surveys were subject to methodological flaws in sampling methods and use of validated instruments. Nonetheless, there is evidence from at least three countries (China, Czech Republic and USA) of increases in suicidal/self-harm thoughts in the general population during the pandemic compared with pre-pandemic levels. Two robustly sampled general population, nationally representative cross-sectional surveys with pre pandemic baseline data from 2017/18 reported a three to four fold increase in suicide risk (Winkler et al., 2020) and suicidal thoughts in low-income households (Raifman et al., 2020), but differences in data collection approaches (i.e. face-to-face vs. on-line) may bias comparisons. Recent studies, with repeat measures of mental health outcomes since the start of the pandemic, also point to rising levels of suicidal thoughts during the pandemic (O'Connor et al., 2020).
The review included 20 service utilisation studies (compared with only three in the previous update), the majority of which identified a drop in frequency of emergency department contacts for suicidal thoughts, behaviours and self-harm. An increase in contacts to a mental health digital platform was identified in one study (Titov et al., 2020), but with no changes in contacts for suicidal thoughts. There have been several recently published service utilisation studies (Carr et al., 2020;Hawton et al., 2020a;Jollant et al., 2020) which reiterate and extend these findings. Jollant et al. (2020) report a 8.5% decrease in hospitalisation for self-harm, greater in females than males, in France in January to August 2020 compared with the same period in 2019. There was also an increase in use of some more lethal methods (firearms / jumping/ drowning) as well as a rise in in-hospital deaths and ITU admissions. Carr et al. (2020) report a 30% fall in consultations for self-harm in April to June 2020 in primary care and secondary care in the UK, the former a setting not explored in currently included studies. They highlight that the treatment gap for depression and anxiety was greater in working age adults, for practice populations in deprived areas, and for self-harm. A limitation of all studies based on hospital presentations is that they may not reflect community prevalence of suicidal thoughts and behaviours. This may be a particular issue if people were deterred from presenting to hospital because of fears of either overburdening already stretched healthcare systems or of contracting the virus in these settings themselves. That said, those who present to services may be able to give some insight into whether COVID-19-related concerns are important. In one UK study, 'stay-at-home' related issues contributed to around half of cases, more so in males than females. The most frequent COVID-related factors were mental health issues, including new and worsening disorders, cessation, reduction or transformation of services (including absence of face-to-face support), isolation and loneliness, reduced contact with key individuals, disruption to normal routine, and entrapment (Hawton et al., 2020b).
Modelling studies that aimed to predict the impact of the pandemic on national or global suicide rates produced widely differing estimates of the likely impact and most focused on predictions based on previous studies of the impact of changes in unemployment levels on suicide. These differences between model estimates were partly due to differences in modelling assumptions, which are themselves in turn associated with considerable uncertainty. Given the methodological limitations, the uncertainty of assumptions about how the economies of individual countries will be affected, as well as international differences in financial supports given to businesses and people out of work, these predictive exercises can at best only provide a guide as to where action and available suicide prevention strategies should be directed.
Studies of social media posts potentially provide another insight into the impact of the COVID-19 pandemic on suicide risk and have the potential to provide more-or-less real time assessments of changes in risk. The two studies we identified (Low et al., 2020;Saha et al., 2020) reported heightened levels of suicide-related posting/suicidality. However, there are several limitations to this approach making these studies hard to interpret, including: self-selecting biases in respect of who contributes to these fora (and when); the unit of analysis being posts/tweets rather than individuals so multiple posts may be from the same individual; and the dissemination of misinformation; the demographic and clinical characteristics of the people making the posts are unknown; and whether comments reflect their own distress or more general concerns is uncertain.
It is also not clear whether mentions of suicide on social media posts map to actual rates of suicidal thoughts in the community and whether this changes in particular contexts and over time. The nature of the relationship (if any) between social media reports and behavioural change in the context of suicide needs to be better understood. Insights derived from such approaches may help deepen our understanding of the mental health challenges of the pandemic and how these may change over time. Future research could usefully try to segment the posts by individuals and sociodemographics to explore changes in sub-groups. Another potentially useful approach to assessing the impact on COVID-19 on population mental health and suicide risk is analysis of Google trends data (Jacobsen et al., 2020;Knipe et al., 2020;Rana, 2020;Sinyor et al., 2020), but we excluded such studies from our review as we think that search data constitute an even weaker proxy for population mental health.
We identified 25 case series of suicide attempts and suicide deaths, 14 based on news stories in India, Bangladesh and Pakistan. Given the relatively low quality of case series in the hierarchy of evidence, often reflecting small numbers and selection bias, but more importantly the lack of comparator data, drawing any reliable inferences from these studies is inherently flawed. Furthermore, news reports report a nonrepresentative sample of suicide deaths and often derive their information from bystanders and witnesses who are unlikely to know the full circumstances of the death (Khan et al., 2009). However, in parts of the world without reliable suicide incidence data they may be the only source of information (Khan & Hyder, 2006). Nevertheless, these studies highlight circumstances surrounding apparently COVID-19-related suicides and flag the potential importance of factors such as economic difficulties, fear of the disease, alcohol withdrawal and social isolation even in young people and children.
Only 14% (11/78) included studies specifically focussed on children and young people. An early report (data up to May 2020) provided some reassurance about the impact of public health measures/school closures on suicide rates in children (<20 years) in Japan (Isumi et al., 2020). However, more recent data (Tanaka & Okamoto, 2021;Ueda et al., 2021) flags a concerning rise amongst students and young (<40 years) people, particularly females and children and adolescents during the second wave of the pandemic and school closure. Three were cross-sectional surveys with attendant methodological flaws. Two surveys were conducted in university student populations (Debowska et al., 2020;Hamza et al., 2021) in 11 universities with predominantly female respondents. No statistical evidence of a rise in suicidal thoughts or self-injury was found over a number of waves of data collection. Wang et al's (2020) network analysis of symptoms of anxiety and depression in young people highlighted an increasing connection between 'too much worry' and suicidal thoughts. It is challenging to assess how generalisable these findings from China are to other countries and other phases of the pandemic. If generalisable, it could point to some treatment targets that are more central to suicide risk, but this is not yet clear. Zhang et al's (2020) cohort study reported pre-pandemic comparison data, with increases seen in NSSI, suicidal thoughts, suicidal plans and suicide attempts in primary and secondary school children post-pandemic. However the sampling frame was poorly reported so representativeness of the sample is challenging to assess. Only one of the service utilisation studies focussed on this age group (Sheridan et al., 2021) but this was based in a single tertiary centre; although another study of a broader age range included them (Walker et al., 2020). There were two case series focussed on children and young people (Jefsen et al., 2020b;Jolly et al., 2020). The stressors identified for adolescents included the inability to see friends, arguments with parents, unresolvable arguments via social media, academic stress and feelings of isolation (Jolly et al., 2020).
Only three included studies focussed on frontline healthcare staff. Two were case series (Kapilan et al., 2020;Rahmen et al., 2020) based on news reports of six or eight nurses deaths (i.e. there is potential duplication of reports of the same deaths). Factors reported as associated with deaths included: fear they had become infected; positive test result; being in quarantine; fearful of becoming infected; and " extreme stress and mental disturbance". The third, a case control study, reported that the prevalence of suicidal thoughts was no higher in medical staff who were in direct contact with COVID-19 patients, compared to those who had no direct contact (Cai et al., 2020).

Strengths and limitations
The literature exploring COVID-19 and suicide deaths, suicidal behaviours, self-harm and suicidal thoughts is expanding rapidly. Since our last review end-date (i.e. between 7 th June 2020 to 19 th October 2020) we identified a further 4156 potentially eligible studies. While most of the published evidence that we identified in this update had important limitations there was a marked improvement in study quality compared with our last update. Importantly, a large volume of the literature remains not peer reviewed; some reports are pre-prints, so this may change, but a number are research letters. All included studies remain observational in design and thus potentially prone to multiple sources of bias (e.g., recall bias, selection bias, confounding).
A number of the studies included in this update used nonprobability samples e.g. convenience samples of volunteers recruited via the Internet. Such studies tend to attract volunteers who have access to the internet, are already engaged in research or have an interest in the topic. When assessing suicidal thoughts and behaviours, those in most distress or with co-existing mental illness, as well as older people, may be less likely to participate. Therefore prevalence estimates and associations observed among healthy volunteers may not reflect associations that would be seen in representative samples (Pierce et al., 2020). However, such study designs potentially provide potentially valuable information at the very early stages of a health crisis, where the timeliness of studies to inform policy and practice is important and repeated cross sectional studies provide valuable evidence about changing levels of population mental health and risk factors (e.g. O'Connor et al., 2020;Raifman et al., 2020). More consistent reporting of sampling frames, repeat survey and the use of validated measures will ensure they make a more meaningful contribution to the evidence base.
There is a paucity of research focussing or reporting on ethnic minorities within populations, children and young people, the bereaved and frontline health and social care staff, which needs to be addressed. Synthesis of findings across studies, and both between and within countries, is confounded by the timing of data collection; differences between studies may be due not only to methodological differences, but also differences in the extent and stringency of public health prevention measures (physical distancing), economic disruption and COVID-19 infection rates in the any population at the time data are collected. A final limitation of the review is that, due to resource limitations, we excluded grey literature (e.g. Fancourt & Steptoe, 2020; National Child Mortality Database, 2020)

Implications
There is thus far no clear evidence of an increase in suicidal behaviour or self-harm associated with the pandemic, nor with the measures taken to curb the spread of COVID-19, although signals from some repeated population surveys and suicide trend data from Nepal and Japan are concerning. There are suggestions of increased risk in people who have been infected with COVID-19, in line with findings from studies showing increased risk of mental health problems in survivors of COVID-19 (Taquet et al., 2021). Declines in levels of hospital presentation for suicidal behaviour may reflect a real decline in suicidal behaviours early in the pandemic perhaps due to the recognised impact of periods of acute stress / national crisis (e.g. wars) on suicide rates or unmet need in the community, with people cautious about overburdening clinical services or of their own risk of contracting COVID-19 (John et al., 2020a). There is a relative lack of high quality studies to inform prevention in Low and Middle Income Countries and in disadvantaged groups, although studies point to an emerging risk in the latter (Mitchell & Li., 2021). There are, as yet, no studies that assess the effectiveness of strategies to reduce the risk of suicide deaths, suicidal behaviours, self-harm and suicidal thoughts, resulting from the COVID-19 pandemic; such research is urgently required.
Our living review provides a regular synthesis of the most up-to-date research evidence to guide public health and clinical policy to mitigate the impact of COVID-19 on risk of suicidality. However, the rapid growth of research in this area necessarily makes the reporting of the large volume of included studies brief. Therefore in the future we plan to publish timely updates focussed on specific topics like suicide rates, for instance, or in specific populations such as children and adolescents, those with confirmed COVID-19 or healthcare workers. Our future updates will also focus on studies investigating suicide deaths, suicide attempts and self-harm. We will no longer include studies: with suicidal thoughts and "suicide risk" as outcomes; modelling studies (since these have been superseded by studies based on suicide deaths) and those based on social media posts (because of the lack of evidence for diagnoses and self-selecting biases in respect of who contributes to these).

Dissemination of information
This living review, along with further updates, will be published via F1000Research. This review was registered on PROSPERO, with ID CRD42020183326. The protocol is available. All further data are publicly available via our Harvard Dataverse repository including all results of the continuous evidence surveillance and screening. Findings from the review will be widely disseminated through conference presentations, policy briefings, peer-reviewed publications, a project website (https://covid19-suicide-lsr.info/), and traditional and social media outlets.

Study status
We are currently searching and screening on a daily basis.

Ethics and dissemination
Since this is a systematic review, ethical approval is not required. This is an open access peer review report distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Gonzalo Martinez-Ales
Mailman School of Public Health, Columbia University, New York, NY, USA This manuscript is a great scientific contribution. The main strength of the manuscript (that it builds on a remarkable effort --their living systematic review) goes hand in hand with the most important limitation (the period included in the particular iteration that is under consideration for publication). I would like to thank the authors for such a great addition to science (the living systematic review) and express my admiration. Next, I expand on these observations.
The introduction is right on target and reads well. A reference to recent increases in gun purchases in the US (e.g., https://www.businessinsider.com/gun-sales-boom-2020-backgroundchecks-hit-record-highs-2021-1). Methods are sound. Results are concise and informative. The tables are particularly interesting and we congratulate the authors on the table including modelling studies as it conveys the most important information easily. The discussion also reads well and adjusts well to the findings.
There is, however, a major limitation to this study that authors may want to address: the limited period of time included. This iteration of the review stopped including papers by July 7th, roughly 4 months after the pandemic hit Western countries for the first time. Notably, this review would have been of great interest if published over the summer. Several research reports (and important grey literature) have become public in the meantime, some adding to the evidence reviewed here without notably changing the overarching results but enhancing their reliability (and probably creating the necessary ground for a quantitative summary or a meta-analysis) and, more importantly, some creating groundbreaking evidence that may change the conclusion of this review (such as the Nature Comms paper by Tanaka and Okamoto using data from Japan to show an initial dip and subsequent increase in suicide rates in Japan).
See some key recent key additions to the literature as an example: https://www.nature.com/articles/s41562-020- The impact of this profound and sound review is somewhat limited by the period included: readers should resort to the authors' ongoing live review.
A limitation of the paper is inadequate attention to study quality in the analysis and interpretation of findings. I will give several examples. First, the authors report that they used a formal tool to assess the risk of bias for epidemiological or clinical trial design studies, but do not report findings from these assessments; given that many papers included in the review were not peer reviewed, it seems especially useful for the authors to use such assessments of study quality to guide their review and to 'weight' findings from these studies in their analysis. Second, the degree of methodological rigor could be assessed for all studies, not just those with epidemiology/clinical trial designs and the authors should consider doing so. Third, the authors indicate in the primary table that letters to the editor were 'probably not peer reviewed.' Given that this information could be verified by contacting the journals, this would be a useful strategy to bolster findings from this review. Fourth, when the authors describe the findings, they do not differentiate between findings that appear methodologically-sound versus those that may not be, thus negating one of the most useful features of review papers for readers.
Another limitation of the paper is that it provides relatively little synthesis or conclusions, which is a key function of review papers, as opposed to a database that contains a listing of available studies. The discussion section includes more of a summary of what studies examined (and did not examine) as opposed to a synthesis of findings. The authors do not provide a nuanced discussion of the fact that these studies come from numerous countries around the world and what addressing this issue could potentially tell us about possible variability in suicide rates around the world. They do not discuss limitations with sampling that appeared across studies (e.g., generalizability of online platforms like M-Turk). In the discussion section, the authors conclude that "a marked improvement in the quality of design, methods, and reporting in future studies is needed." This may be accurate, but I do not think it is an especially useful statement to guide the field. A more useful set of statements might involve a synthesis of methodological strengths and weaknesses as well as a discussion on strategies that can be taken going forward to address these weaknesses. The authors do not posit further implications; this may be accurate-that nothing else can be concluded right now-but in that case, perhaps the paper is premature.
The authors should provide additional details on the methods used for the review process to In the category of what are the effects of other exposures, suicide by railways can be added. In fact there a likely reduction of railway suicides. The other addition could be the impact of working from home, change in workplace etc.