This systematic review has been designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) statement and has been registered on PROSPERO (CRD42020196610) 
Included are: (1) COVID-19 infection patients among adults (≥18 years of age) who are diagnosed with four types of psychiatric and neuropsychiatric syndromes (anxiety (e.g. generalized anxiety, panic attack), depression, delirium, and post-traumatic stress disorder), with no age, gender or setting, location or ethnicity restrictions. (2) psychiatric and neuropsychiatric syndromes diagnosed by a trained researcher or health professional according to the criterion defined by ICD-10, ICD-11, DSM-IV, DSM-V, and Chinese Classification of Mental Disorders - 3 (CCMD-3) or by validated psychometric scales (e.g, clinician—administered PTSD scale for PTSD) with established cutoffs approved by psychologists (RXZ). (3) studies published in English and Chinese.
Excluded are: (1) studies explored the indirect effects of SARS-CoV-2 on the mental health of family members, care providers, or isolated people who did not infect. (2) populations with other coronavirus diseases (severe acute respiratory syndrome (SARS) or Middle East respiratory syndrome (MERS) unless the trial authors provided subgroup data for people with COVID-19). (3) studies in which patients self-reported as anxiety, depression, delirium, and post-traumatic stress disorder, or studies that did not report symptom measurement methods or diagnostic criteria. (4) patients with a prevalence of psychiatric and neuropsychiatric syndromes reported before a diagnosis of COVID-19.
Type of outcomes
The primary outcomes is the prevalence of depression, anxiety, delirium, and PTSD. Secondary outcomes are the incidence of mortality in COVID-19 patients with depression, anxiety, delirium or PTSD, the measurement of health-related quality of life score using Short Form 12 Health Survey Questionnaire (SF-12), or Short Form 36 Health Survey Questionnaire (SF-36). The outcome will be classified as examining the acute or post-illness psychiatric consequences of infection on the basis of whether information is collected during the patient’s illness or the period after the illness.
If a study met our criteria reports on COVID-19 infection that were not specified a priori as outcomes of interest for this review, the results will be noted in a narrative synthesis or reported in the summary of findings table (e.g, symptom severity as defined by different scales), but not necessarily pooled for meta-analyses.
We will include only peer-reviewed cohort studies, cross-sectional studies. We will exclude duplicate publications (i.e, two or more studies investigating the same sample). Conference abstracts, commentaries, or opinion pieces will also be excluded because they lack adequate information for meta-analysis.
A senior investigator (Y.G.) would examine the published and gray literature sources to extract the studies reporting the prevalence of depression, PTSD, anxiety, or delirium in COVID-19 patients. An experienced medical information specialist (J.H.T.) would further check and approve the search methodology. We will conduct a comprehensive search of Cochrane library, PubMed, Web of Science, Embase, and Chinese Biomedicine Literature to extract articles/abstracts published between the inception of this disease (1 December 2019) until the completion of this review will be included. There will be no restrictions on language or year of publication. An additional file, which would describe the complete search strategy for PubMed as well as other electronic databases will be provided. We will also thoroughly search the reference lists of the relevant reviews and research trials. We have presented the search strategy using PubMed as an example in Table 1. The search strategy will be adapted to fit other online databases as well.
We will perform identical search operations at regular pre-defined intervals to identify newly published data. There are no robust standards for the update frequency based on current research; however, due to the unprecedented number of publications on COVID-19, we will update the literature searches every three months, and perform meta-analysis if any new eligible studies or data are obtained. We will submit an updated systematic review if we observe any changes in the outcomes and heterogeneity after the addition of new studies or provide data on additional outcomes [11, 12]. We chose this updating frequency to allow quick updates and to highlight the most recent information to the researchers, clinicians, nurses, and policymakers [11, 14, 16].
Original literature search records will be imported into Endnote X9 software tool (Thomson Reuters, New York, NY, USA) management software. Two authors (JYS and YG) will independently retrieve full-text of potential studies after deduplication to assess their eligibility according to the abovementioned inclusion criteria. The selection process will be conducted under the supervision of a psychologist (RXZ). Any disagreement will be resolved by the reviewer (JHT).
Two independent reviewers (JYS and MMN) will be involved in data extraction; we will extract country of patients, gender, age, sample size, study design (e.g, cohort studies), diagnostic criteria for the viral infection (such as WHO criteria), criteria for the definition of depression, anxiety, delirium, and PTSD (e.g, ICD-11 ), population type (e.g, pregnant women), the severity of the symptoms defined by different scales (e.g, clinician—administered PTSD scale for PTSD), number of signs or symptoms (e.g, depression, anxiety), quality of life scores,timing (acute vs post-illness), and length of follow-up.
Risk of bias (quality) assessment.
Two independent reviewers (JYS and YG) will use the following tools to examine the risk of bias in the included studies: the Newcastle-Ottawa Scale (NOS) for cohort studies . The 11-item checklist recommended by the Agency for Healthcare Research and Quality (AHRQ) will be used to assess the quality of the cross-sectional studies include . We will classify the methodological quality of each individual study as having a low, high, or unclear risk of bias as describing in Table 1. Any disagreement regarding inclusion of some studies will be resolved by discussion and consensus between the two reviewers. If this failed, it shall be resolved by the third reviewer (JHT).
Processing missing data
We will contact the corresponding or other primary authors to obtain missing data or insufficiently reported data after selecting the studies. In addition, we will estimate missing data if they can be extracted from tables or figures. Trials with missing data that cannot be obtained will be excluded for reasons. Any significant deviations between the protocol and the final review will be reported clearly.
The Stata (v13.0; StataCorp) and Revman 5 were used for statistical analysis. The statistical heterogeneity will be examined using the Cochran's Q and the I² statistic. An I² > 50%, and a p-value < 0.05 will correspond to significant heterogeneity, and a random-effects model will be used for the subgroup analyses and pooled estimates. On the contrary, an I² < 50% and a p-value > 0.05 will correspond to insignificant heterogeneity, and the fixed-effect model shall be used for the subsequent meta-analysis. We defined point prevalences for the rate of depression, anxiety, delirium, and PTSD diagnoses. The effect size measures were prevalence with 95% CIs (for number of signs or symptoms, quality of life scores) and mean difference with 95% CI (proportion of depression, anxiety, delirium, and PTSD diagnoses; the incidence of mortality). The heterogeneity/publication bias will be examined using the Egger's test or the symmetry of the funnel plot. In the Egger's test, bias will be significant when p-value < 0.05.
Provided sufficient data is available, the following subgroup analyses will be planned for main outcomes if data are sufficient: age (< 60 vs. ≥ 60 years), setting (developed countries vs. developing countries), gender (male vs. female), databases (data from Chinese databases vs. data from English databases), and follow-up time.
We will perform sensitivity analyses to assess the influence of the study 's methodological risk of bias. To do this, we will repeat any meta-analyses by excluding data from studies classified as a high risk of bias.
Quality of the evidence
The Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) Working Group method will be used to examine the quality of the evidence for each outcome. We will assess each outcome based on each of the following five aspects: imprecision, inconsistency, limitations, indirectness, and publication bias. They will be rated as very-low, low, moderate, or high level [19, 20].