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 Table of Contents  
ORIGINAL ARTICLE
Year : 2020  |  Volume : 4  |  Issue : 2  |  Page : 181-189

A cross-sectional study of psychological distress and fear of COVID-19 in the general population of India during lockdown


1 Department of Psychiatry, Mahatma Gandhi Institute of Medical Sciences, Wardha, Maharashtra, India
2 Department of Psychiatry, BRLSABVM Government Medical College, Rajnandgaon, Chhattisgarh, India

Date of Submission15-Jun-2020
Date of Decision12-Jul-2020
Date of Acceptance27-Jul-2020
Date of Web Publication25-Nov-2020

Correspondence Address:
Dr. Anantprakash Siddharthkumar Saraf
BRLSABVM Government Medical College, Rajnandgaon, Chhattisgarh
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/aip.aip_54_20

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  Abstract 


Context: With relatively high transmission rate and fatal potential, the COVID-19 pandemic is responsible for widespread fear and psychological distress all over the world, including India. Aim: Assessment of these problems in the general population is the first step to address this problem. Settings and Design: We did an online survey using snowball sampling strategy through various social media communication platforms. Materials and Methods: Semi-structured format was used to collect sociodemographic data and COVID-19-related information. The Kessler's Psychological Distress Scale (K10) and the Fear of COVID-19 Scale were used for assessment psychological distress and fear, respectively. Results: A total of 530 study respondents had adequate participation from all socioeconomic strata, diverse educational and professional backgrounds, and from all parts of the country. Majority of the participants were from red zone districts of lockdown (72.8%) and considered the imposed lockdown as essential (98.7%), although many of them reported negative impact on their psychological state (38.9%). A substantial number (38%) of people reported psychological distress significantly (P < 0.05) associated with females, unmarried, students, lower socioeconomic status (SES), caretakers of COVID-19 patients, poor perceived physical health, and higher score on the Fear of COVID-19 Scale. Female participants and those belonging to lower SES and a red zone district also reported significantly (P < 0.05) higher degree of fear of COVID-19. Despite this, only about 10.9% of the respondents sought help through telephonic or online counseling and most (91.4%) of them found it helpful. Conclusions: The impact of COVID-19 pandemic on psychological health is catastrophic. Planned measures at local as well as national level are essential to avert this crisis.

Keywords: COVID-19, fear, lockdown, online counseling, pandemic, psychological distress


How to cite this article:
Sathe HS, Mishra KK, Saraf AS, John S. A cross-sectional study of psychological distress and fear of COVID-19 in the general population of India during lockdown. Ann Indian Psychiatry 2020;4:181-9

How to cite this URL:
Sathe HS, Mishra KK, Saraf AS, John S. A cross-sectional study of psychological distress and fear of COVID-19 in the general population of India during lockdown. Ann Indian Psychiatry [serial online] 2020 [cited 2021 Apr 20];4:181-9. Available from: https://www.anip.co.in/text.asp?2020/4/2/181/301435




  Introduction Top


The novel coronavirus disease (COVID-19) pandemic started from the Wuhan city in Hubei province of China in December 2019 and has spread to over 200 countries in the world affecting more than 7 million people and causing more than four lac deaths.[1] To curb the spread of COVID-19 in India, the Government of India imposed a nationwide lockdown starting from March 24, 2020, mandating total restriction on movement outside the house except for essential supplies or other emergency reasons. With the complete suspension of all means of transport for people and closing down of educational institutes, industries, and other services, the lockdown had a significant economic and psychosocial impact.[2] In the second phase of lockdown, the districts in the country were stratified into three zones based on cumulative cases reported and the doubling rate. The red, orange, and green zone classification saw different levels of relaxation of lockdown measures and allowance of mobility along with partial resumption of normal activities.[3]

Plethora of psychosocial issues such as infection fears, frustration, boredom, lockdown impact, an overflow of misinformation (infodemic), rumors, multiple conspiracy theories, inadequate supplies, financial loss, and stigma about the infection have taken their toll on mental health globally during this pandemic.[4] The two main consequences of these issues, namely fear and psychological distress, have received lesser attention than containment of infection and developing an effective treatment and vaccine. Fear impairs rational thinking and aggravates the crisis.[5] There are a few recent reports from India of people committing suicide due to fear of being infected by COVID-19.[6] Hence, efforts for addressing psychological distress and fear should be at par with the measures for controlling the pandemic. Quantification of fear and distress in the population, which has been attempted in our study, is the first step in this direction.

Interventions are necessary to reduce psychological distress as well as fear. Numerous public as well as private sector organizations in India came forward to offer online help to people experiencing psychological distress.[7] However, the level of use of such resources by the distressed and adequacy of these interventions in providing solution to the psychological crisis has not been assessed. Hence, the authors conducted this study in the present form using new-age technologies, considering the need for social distancing and travel restrictions imposed by the lockdown.


  Materials and Methods Top


Study design and data collection

This was a cross-sectional, observational, and descriptive study. Ethical clearance was obtained from the institutional ethics committee. The online semi-structured questionnaire for the study was prepared using Google Forms (freely available online application by Google). The sample was collected using a snowball sampling strategy. A message requesting people to participate in the study, which included link to the study form, was shared with the contacts of authors all over the country through text messaging, E-mails, and social media platforms such as WhatsApp and Facebook. The participants were requested to forward the message further to their contacts. Participants from all over the country with age more than 18 years, able to understand English and Hindi, with access to the Internet and smartphone, and willing to give informed consent were included. Data were collected in the sixth week of lockdown (from April 29 to May 3, 2020), when the third phase of lockdown was about to end. It was an ideal time to measure the psychological distress and fear in the population as the measuring instruments assess the mental state over the past 1 month. About 548 people responded to the questionnaire. After checking for completeness and consistency, data of 530 respondents were included in the analysis (response rate: 96.7%).

Tools

The questionnaire for the form contained four sections, which took around 5–10 min to complete. A short title of the study, name and E-mail address of the principle investigator, directions for filling the form, and informed consent consisted of the first section. The consent was in a simple understandable language and included exact title and purpose of the study, the statement of confidentiality of information, and the right to withdraw. The remaining sections of the questionnaire would open only after the individual has ticked the box stating, “I consent to participate in the study.” The confidentiality and anonymity of the data were maintained throughout the process.

The second section of the form collected information about sociodemographic profile such as age, gender, marital status, education, occupation, place of residence, household income, and total number of family members. The respondents from various districts across India were further classified into different zones (red, orange, or green) in accordance with the Ministry of Health and Family Welfare notification.[3] This part of the form also had questions about the COVID-19-related information such as their knowledge of the pandemic, their opinions on lockdown, and psychological impact of it. Apart from previous history of mental health problems and substance abuse, a single-item questionnaire for self-perceived physical health status change after the outbreak of the infection was included.[8]

The third and fourth sections consisted of the Kessler's Psychological Distress Scale (K10)[9] and the Fear of COVID-19 Scale.[5] The K10 Scale has 10 questions answered on a five-point Likert scale to assess the emotional state of a person. The self-rated scale is used as a screening instrument for psychological problems such as depression and anxiety in the general population, and higher scores on the scale warrant further clinical assessment in an individual to confirm the diagnosis. The K10 Scale was chosen for the current study considering its brief nature, good reliability, and validity.[9] The cutoff scores adopted by the Victorian Population Health Survey were used in statistical analysis to classify the respondents' level of distress in mild, moderate, and severe categories.[10] The last past of the form also included contact details of the authors, in case any participant needed any psychological help.

The Fear of COVID-19 Scale is a novel self-rated scale developed after the coronavirus outbreak and has been validated for assessing fear in the general population and has robust psychometric properties (Cronbach's α: 0.82).[5] In this scale, the participants score their level of agreement on a five-point Likert scale to seven statements relating to fear about coronavirus disease 2019. Higher overall scores indicate more severe fear of COVID-19.[5] For the purpose of statistical analysis, the authors divided the total score (from 7 to 35) into tertiles to represent mild (7–15), moderate (16–25), and severe (26–35) levels of fear of COVID-19.

Statistical analysis

The data were pooled, tabulated, and analyzed using SPSS software version 23 (IBM Corp., Armonk, NY, USA). Descriptive statistical analyses were used to summarize categorical data as frequency and percentages and continuous variables as mean and standard deviation. Inferential statistical analyses included Chi-square tests and Fisher's exact test to compare categorical variables and Pearson's correlation for continuous variables. Linear regression analysis was done using stepwise variable selection to determine significant predictors of psychological distress. Statistical significance was determined at P < 0.05.


  Results Top


Sociodemographic characteristics

The mean age of the study sample was 32.45 years with standard deviation of ± 12.22 years, ranging from 18 to 79 years. There was almost equal participation from both the genders (283 males, 53.4%, and 247 females, 46.6%). Almost equal number of participants were married (n = 235, 44.3%) and unmarried (n = 287, 54.2%). Most of the participants belonged to urban (n = 283, 53%) and metro areas (n = 170, 32.1%). Majority of the respondents were graduates (n = 262, 49.4%) and postgraduates (n = 194, 36.6%). Students (n = 152, 28.7%) consisted of around one-third of the respondents, and others were homemakers (n = 33, 6.2%), businessperson (n = 68, 12.8%), government employee (n = 53, 10%), private employees (n = 165, 31%), and others (n = 57, 10.8%). There were almost equal number of upper (socioeconomic status [SES] I = 251, 47.4%) and lower-middle and lower (SES IV and V = 279, 52.7%) SES people according to the BG Prasad Scale[11] [Table 1].
Table 1: Sociodemographic characteristics

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COVID-19-related characteristics

Majority of the respondents were from COVID-19 red zone (n = 386, 72.8%) and the rest from orange (n = 70, 13.2%) and green zones (n = 74, 13.2%). Almost everyone had heard about the novel coronavirus disease 2019. Out of 530 respondents, only 7 (1.3%) had tested positive for COVID-19 and 41 (7.7%) were directly involved in the care of COVID-19 patients. About one-third (n = 178, 33.6%) of the respondents were health-care workers. Almost everyone (n = 523, 98.7%) considered the imposed lockdown as essential, although a substantial number of individuals (n = 206, 38.9%) reported that the lockdown had negative impact on their emotional state. About 31 participants (5.8%) reported already having mental health problem. About 13% (n = 70) reported the use of alcohol during the last 1 month and 5.8% (n = 31) reported using both alcohol and tobacco. About 8.9% (n = 47) of the respondents reported alcohol or other drug abuse on a regular basis even during the lockdown. Worsening of perceived physical health status in the outbreak was reported by 12.7% (n = 67), although 61.5% did not perceive any change, and interestingly, 25.8% of the respondents perceived betterment in their physical health during lockdown [Table 2].
Table 2: Coronavirus disease-19-related characteristics

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Level of psychological distress

The mean score on the K10 Scale was 19.12 ± 8.05. About 14.9% (n = 79) reported mild distress, 10.8% (n = 57) moderate distress, and 12.8% (n = 68) severe distress [Table 3]. Chi-square test showed distress to be significantly associated (P < 0.05) with female gender, unmarried or divorced/separated status, students, lower-middle and lower SES, and severity of psychological distress [Table 4]. No significant association was found between residence, educational level, stream of education, and religion and psychological stress. Participants who felt that lockdown had negative impact on their emotional state and reported worsening of their physical health had significantly more level of psychological distress. On applying Fisher's exact test, it was found that people with preexisting mental health problems and those who were taking care of COVID-19 patients were significantly (P < 0.05) more distressed. No significant association was found between attitude toward lockdown or the lockdown zones in which participants were currently residing and psychological stress [Table 5]. Pearson's correlation analysis (r = 0.283) showed a significant association (P < 0.05) between K10 and Fear of COVID-19 Scale scores.
Table 3: Level of psychological distress, fear of coronavirus disease-19, and help seeking

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Table 4: Factors associated with psychological distress

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Table 5: Factors associated with coronavirus disease-19 fear

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Level of fear of COVID-19

The mean score on the Fear of COVID-19 Scale was 15.73 ± 5.22. About half of the respondents (50.4%, n = 267) reported mild and 46.6% (n = 247) reported moderate degree of fear of COVID-19. Only about 3% (16) of the respondents reported severe degree of fear [Table 3]. Significantly higher levels of fear were found in females, those in lower-middle and lower SES, residents of red zone of lockdown, and those with poor perceived physical and emotional health status (P < 0.05) [Table 5].

Help seeking during lockdown for psychological distress and fear

Only about 10.9% of the respondents sought help through telephonic or online counseling, out of which 91.4% found it helpful [Table 3]. Participants with severe level of psychological distress were significantly (P < 0.05) more likely to seek telecounseling [Table 4].

Predictors of psychological stress

By applying multivariate linear regression analysis through stepwise method, female gender, unmarried status, preexisting mental health problems, regular use of substances of abuse, perceived negative impact of lockdown on emotional state, being tested positive for COVID-19, and higher level of fear of COVID-19 were found to be significant (P < 0.05) predictors of psychological distress, explaining 35% of the variance (adjusted R2 = 0.351).


  Discussion Top


Our study sample has participation of individuals from diverse socioeconomic, regional, educational, and professional backgrounds, allowing for credible assessment of factors associated with psychological distress and fear of COVID-19 among the Indian population. Urban and metropolitan graduates and postgraduates dominated study sample, which can be attributed to their awareness and familiarity with the technological tools used for the survey. Unavailability of smartphones or lacking necessary skill to fill the form could be a reason for lesser participation from rural and lesser-educated people. The predominant response from red zone areas could have been because of sampling bias, due to more concern and vigilance among them as compared to other areas.

Although nearly 39% of the participants admitted that the lockdown has impacted their emotional state negatively, most of them considered lockdown imposed by the government as essential, thereby portraying the success of the government in convincing the population about the necessity of drastic measures, even in the face of personal discomfort and stress. About one-fourth of the people reported betterment in perceived physical health status, which shows positive coping and viewing lockdown as an opportunity for rest and rejuvenation by a significant number of people.[12] On the other hand, a substantial number of people reported continued use of substances of abuse even during pandemic and lockdown, highlighting drug abuse as a harmful coping strategy.

Over 38% of the study population suffered from psychological distress as measured on the Kessler's Psychological Distress Scale (K10). These findings are similar to two other nationwide surveys done in China.[13],[14] In an Italian survey on psychological impact of COVID-19 on the general population, more than 26% of the participants showed high-stress levels.[15] Differences in measuring instrument, population characteristics, or a different stage of the COVID-19 pandemic may explain the difference from our observations. However, the same study showed approximation of depression (32%) and anxiety (18%) figures with high-stress levels. Considering higher psychological distress levels, we may be looking at a catastrophic impact of the COVID-19 outbreak on the mental health of the Indian population.

Female gender, single status, being a student, belonging to lower SES, having COVID-19 infection or being involved in the care of COVID-19 patients, and poor perceived physical health were significantly related to higher levels of psychological distress. An observational study conducted in China earlier this year also concluded that female gender, student status, and poor self-rated health status are predictors of depression and anxiety.[14] The perceived health status has shown to vary in a cyclical fashion with psychological distress. The decline in the former with the escalation of later has been associated with future functional disability.[16] Similar experiences were reported in the SARS epidemic.[17] These findings advocate the need to pay special attention to the unmet needs of these target groups through effective policy measures at local as well as national level. In FEEL-COVID survey done on the Indian population using similar sampling method in earlier part of lockdown, 33.2% of the individuals were found to have the adverse psychological impact of COVID-19 pandemic.[18] A higher number of people with psychological distress (38%) and of fear of COVID-19 (50%) in our study done in later part of lockdown highlight the increasing psychological impact and fear with the increasing number of cases and duration of lockdown.

Hypochondriacal fears of acquiring infection have shown to give rise to panic symptoms.[19] In previous studies done on the Indian population, people were found to be preoccupied with the thoughts of COVID-19, having difficulty in sleeping, and having paranoia of acquiring Coronavirus infection.[20] Our study echoes previous studies showing a large proportion of people suffering from fear of COVID-19. Female gender, lower SES, and belonging to a red zone district were significantly associated with fear, which might be due to marginalization and stigma. In our study, level of psychological distress was significantly correlated with fear of COVID-19. During the SARS also, the fear of infection was found to be associated with high levels of stress and depression and loss of sleep.[21]

The frequency of use of online counseling services was found to be very low in our study, signifying that the concept of online counselling is relatively new, and systematic efforts are needed to get the masses acquainted with this new modality of service delivery. Experience from China suggests that the online platforms developed for the aid of those experiencing adverse psychological impact are helpful.[22] Furthermore, a lot of psychological distress and fear arising from misinformation or misconception can be prevented by effective use of social media.[23] Having organized services for psychological crisis intervention is the need of an hour in India.

Limitations

Being an online survey, participation from significant proportion of the population not having access to technological tools was lacking. This demands caution while generalizing the findings of the study to the whole population. Small sample size and snowball sampling strategy also limit its scope, and larger studies with randomized sampling are needed for better predictions. Furthermore, the tool used for assessing fear of COVID-19 is relatively new, and the cutoffs were arbitrarily chosen for the sake of statistical analysis; further validation and factor analysis in the Indian population is warranted.


  Conclusions Top


In this study, we found that the COVID-19 pandemic has a significant psychological impact, and its mental health-related ramifications will be wide and far reaching in the near future. It emphasizes the need for intensifying our efforts to effectively plan and implement wide range of activities and programs, especially targeted at vulnerable groups, both during and after the pandemic.

Ethical statement

This study was approved by Institutional Ethics Committee with reference number MGIMS/IEC/PSY/61/2020 obtained on May 2,2020.

Declaration of patient consent

The patient consent statement was taken from each patient as per institutional ethics committee approval along with consent taken for participation in the study and publication of the scientific results/clinical information/image without revealing their identity, name, or initials. The patient is aware that though confidentiality would be maintained anonymity cannot be guaranteed. The informed consent form was an integral part of the first section of online form, and individuals who consented only could proceed to further sections.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
World Health Organization. WHO Timeline-COVID-19; 2020. Available from: https://www.who.int/news-room/detail/27-04-2020-who-timeline-covid-19. [Last accessed on 2020 Jun 02].  Back to cited text no. 1
    
2.
Singh KD, Goel V, Kumar H, Gettleman J. India, Day 1: World's Largest Coronavirus Lockdown Begins. The New York Times; 2020. Available from: https://www.nytimes.com/2020/03/25/world/asia/india-lockdown-coronavirus.html. [Last accessed on 2020 Jun 04].  Back to cited text no. 2
    
3.
Ministry of Health and Family Welfare. COVID-19: List of Zone Wise Classification in Red, Orange & Green; 2020. Available from: https://taxguru.in/corporate-law/covid-19-list-zone-wise-classification-red-orange-green.html. [Last accessed on 2020 May 31].  Back to cited text no. 3
    
4.
Jakovljevic M, Bjedov S, Jaksic N, Jakovljevic I. COVID-19 pandemia and public and global mental health from the perspective of global health security. Psychiatria Danubina Medicinska Naklada Zagreb 2020;32:6-14.  Back to cited text no. 4
    
5.
Ahorsu DK, Lin CY, Imani V, Saffari M, Griffiths MD, Pakpour AH. The fear of COVID-19 Scale: Development and initial validation. Int J Ment Health Addict 2020;18:1-9.  Back to cited text no. 5
    
6.
Goyal K, Chauhan P, Chhikara K, Gupta P, Singh MP. Fear of COVID 2019:First suicidal case in India! Asian J Psychiatry 2020;4949:101989.  Back to cited text no. 6
    
7.
Indian Psychiatric Society. IPS: State-wise list of Professionals Volunteering for Online Mental Health Services; 2020. Available from: https://indianpsychiatricsociety.org/ips-online-mental-health-services-support-during- covid-19-pandemic/. [Last accessed on 2020 Jun 07].  Back to cited text no. 7
    
8.
Kang L, Ma S, Chen M, Yang J, Wang Y, Li R, et al. Impact on mental health and perceptions of psychological care among medical and nursing staff in Wuhan during the 2019 novel coronavirus disease outbreak: A cross-sectional study. Brain Behav Immun 2020;87:11-7.  Back to cited text no. 8
    
9.
Kessler RC, Barker PR, Colpe LJ, Epstein JF, Gfroerer JC, Hiripi E, et al. Screening for serious mental illness in the general population. Arch Gen Psychiatry 2003;60:184-9.  Back to cited text no. 9
    
10.
Department of Human Services. Victorian Population Health Survey 2001: Selected Findings; 2001. Available from: https://www2.health.vic.gov.au/about/publications/policiesandguidelines/Victorian-population-health-survey-2001-Selected-findings. [Last accessed on 2020 May 31].  Back to cited text no. 10
    
11.
Dalvi TM, Khairnar MR, Kalghatgi SR. An update of B.G. Prasad and Kuppuswamy socio-economic status classification scale for Indian population. Indian J Pediatr 2020;87:567-568.:1-2.  Back to cited text no. 11
    
12.
Hindustan Times. Quarantine Workout: Lockdown Exercises to Keep You Fit, Focused and Sane. Hindustan Times; 2020. Available from: https://www.hindustantimes.com/more-lifestyle/quarantine-workout-lockdown-exercises-to-keep-you-fit-focused- and-sane/story-oHykB6bSsWiDf0jOhoRsdI.html. [Last acessed on 2020 Jun 07].  Back to cited text no. 12
    
13.
Qiu J, Shen B, Zhao M, Wang Z, Xie B, Xu Y. A nationwide survey of psychological distress among Chinese people in the COVID-19 epidemic: Implications and policy recommendations. General Psychiatry 2020;33:e100213.  Back to cited text no. 13
    
14.
Wang C, Pan R, Wan X, Tan Y, Xu L, Ho CS, et al. Immediate Psychological Responses and Associated Factors during the Initial Stage of the 2019 Coronavirus Disease (COVID-19) Epidemic among the General Population in China. Int J Environ Res Public Health 2020;17:1729. Available from: https://www.mdpi.com/1660-4601/17/5/1729. [Last accessed on 2020 Jun 07].  Back to cited text no. 14
    
15.
Mazza C, Ricci E, Biondi S, Colasanti M, Ferracuti S, Napoli C, et al. Nationwide Survey of Psychological Distress among Italian People during the COVID-19 pandemic: Immediate psychological responses and associated factors. Int J Environ Res Public Health 2020;17:3165. Available from: https://www.mdpi.com/1660-4601/17/9/3165. [Last accessed on 2020 Jun 03].  Back to cited text no. 15
    
16.
Farmer MM, Ferraro KF. Distress and perceived health: Mechanisms of health decline. Health Soc Behav 1997;38:298-311. Available from: https://www.jstor.org/stable/2955372. [Last accessed on 2020 Jun 03].  Back to cited text no. 16
    
17.
Peng EY, Lee MB, Tsai ST, Yang CC, Morisky DE, Tsai LT, et al. Population-based post-crisis psychological distress: An example from the SARS outbreak in Taiwan. J Formos Med Assoc 2010;109:524-32.  Back to cited text no. 17
    
18.
Varshney M, Parel JT, Raizada N, Sarin SK. Initial psychological impact of COVID-19 and its correlates in Indian Community: An online (FEEL-COVID) survey. Samy AM, editor. PLoS One 2020;15:e0233874. Available from: https://dx.plos.org/10.1371/journal.pone. 0233874. [Last accessed on 2020 Jun 07].  Back to cited text no. 18
    
19.
Furer P, Walker JR, Chartier MJ, Stein MB. Hypochondriacal concerns and somatization in panic disorder. Depress Anxiety 1997;6:78-85.  Back to cited text no. 19
    
20.
Roy D, Tripathy S, Kar SK, Sharma N, Verma SK, Kaushal V. Study of knowledge, attitude, anxiety & perceived mental healthcare need in Indian population during COVID-19 pandemic. Asian J Psychiatr 2020;51:102083.  Back to cited text no. 20
    
21.
Yu HY, Ho SC, So KF, Lo YL. The psychological burden experienced by Hong Kong midlife women during the SARS epidemic. Stress Health 2005;21:177-84. Available from: http://doi.wiley.com/10.1002/smi. 1051. [Last accessed on 2020 Jun 03].  Back to cited text no. 21
    
22.
Xiang YT, Yang Y, Li W, Zhang L, Zhang Q, Cheung T, et al. Timely mental health care for the 2019 novel coronavirus outbreak is urgently needed. Lancet Psychiatry 2020;7:228-9.  Back to cited text no. 22
    
23.
Lin CY. Social reaction toward the 2019 novel coronavirus (COVID-19). Soc Health Behav 2020;3:1.  Back to cited text no. 23
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  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]



 

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