English language literature was searched in electronic databases viz. Medline via PubMed, CINAHL, Web of Science, Scopus and PsychInfo, and additionally, we searched EPPI mapper and Google Scholar. The search was restricted to publications on or after January 1, 2010, in order to obtain the most recent evidence on newly emerging infectious disease outbreaks.

Using keywords and related terms, a comprehensive search strategy was employed for each database. Keywords used were (social isolation, social distancing, social marginalization, social-alienation, quarantine, self-quarantine, self-isolation), AND (pandemic, epidemic, outbreak, disease outbreak, infectious disease outbreak, severe acute respiratory syndrome, SARS, MERS hemorrhagic fever, avian flu, Ebola, influenza, middle east respiratory syndrome, coronavirus, COVID-19, coronavirus, SARS CoV, SARS CoV-2), AND (mental health, mental health disorders, psychological wellbeing, psychological stress, post-traumatic stress disorder, PTSD, depression, separation, anxiety, loneliness, psychological, suicidal thoughts, suicidal ideation panic attack). The full PubMed search strategy is provided as Extended data.

Journal publications reporting information on any intervention targeted to prevent or control mental health disorder associated with infectious diseases, with no restriction on population, were included. Common mental health disorders were operationalized as anxiety, depression, panic disorder, post-traumatic stress disorder (PTSD), obsessive compulsive disorder (OCD) and simple phobia. Any emerging and re-emerging acute infectious diseases were eligible for inclusion. However, we excluded long standing infectious diseases such as HIV and tuberculosis. Population groups considered were frontline HCWs, mental health patients, vulnerable population viz. older adults and children, other essential workers and general population, during an infectious disease outbreak.

In this narrative review, for replicable or reproducible methodology, we have followed few of the steps of a systematic review. Articles were screened by five authors (BTV, ER, JB, SSP, and VSD) independently, forming pairs of two for title/abstract screening. However, for full text screening we divided the articles between five authors and therefore, independent screening was not followed.

Relevant data were coded from included full texts in a pilot tested coding form by five authors (BTV, ER, JB, SSP and VSD). The results in this narrative review were thematically synthesized based on various strategies and interventions. EndNote X7 software was used for data management. We have briefly summarized the population affected, different range of common mental health disorders, predicting factors of these disorders, and control and prevention of these disorders during infectious disease outbreaks.

Included publications were a mix of original research articles, reviews, and systematic reviews including rapid reviews, from across the world. We excluded editorials and commentaries. Most publications were on the current ongoing COVID-19 pandemic, however, we also identified studies conducted during MERS, ^{24 , 43– 46} SARS, ^{47– 49} Ebola, ^{50– 52} H1N1 Influenza ⁵³ and other infectious disease outbreaks. ^{23 , 54– 58}

We summarized the possible strategies and interventions for common mental health disorders, associated with infectious disease outbreaks. Figure 1 provides snapshot of population affected, common mental health disorders and interventions that help in maintaining or improving mental health wellbeing.

Emerging and re-emerging infectious diseases are a constant threat to the entire world. ^{59 , 60} During an infectious disease outbreak, almost all people, irrespective of age and gender are vulnerable to common mental health disorders. ⁶¹ However, the risk and severity of these disorders may vary between different people. Populations that mostly experienced common mental health disorders were (a) general population ^{62– 67} ; (b) children and youth ^{12 , 63 , 67– 69} ; (c) older adults ^{63 , 70} ; (d) people with existing chronic conditions and mental illness ^{63 , 65– 67 , 70} ; (e) disability or developmental disorders ^{65 , 71} ; (f) people isolated/quarantined and infected with infectious diseases ^{65– 67 , 71} ; (g) caregivers ⁶³ ; (h) underprivileged community ⁶³ ; and (i) healthcare staff. ^{62 , 65– 67 , 70}

A wide range of mental health disorders with varying prevalence, affecting all populations and requiring immediate attention, surfaced during infectious disease epidemics. Table 1 outlines the mental health disorders reported during various infectious disease outbreaks. These mental health disorders affected general wellbeing. ^{64 , 72– 76} There was high pooled estimated prevalence of anxiety (25-46% ^{62 , 67 , 78 , 84 , 85 , 87 , 90} ), distress/stress (13.4-41.1% ^{67 , 78 , 84 , 87 , 90 , 92} ), PTSD (33% ^{78 , 92} ), and depression (22-33.7% ^{67 , 78 , 84 , 87 , 90 , 93} ).

Prevalence of anxiety was higher among quarantined individuals (57.9%), people living with non-communicable diseases (NCDs) (40-55.4%), COVID-19 positive cases (8-47%), the general population (29.8-56%), HCWs (29.0-49%), students (28.2%) and other medical staff (19.9%). ^{62 , 67 , 90} Prevalence of depression was higher among COVID-19 positive cases (41.7-55%), quarantined individuals (38.8%), people living with NCDs (44.8%), students (34.8%), physicians and nurses (25-31.0%), and other medical staff (14.1%). ^{67 , 90} More information on burden and factors associated with common mental health disorders, during the infectious disease outbreaks, is provided as Extended data.

i.

Providing accurate, timely information and ensuring adequate supplies of daily need essentials:

Many strategies have been advocated to address the overall wellbeing of the people during an epidemic. One of the commonly used strategies to reduce burden of psychological stress (applicable for all population groups) is primary prevention strategy that can be broadly characterized as ‘first-aid mental health intervention’. ⁵³ Components of this strategy include providing precise and timely information, in the form of government guidelines, regarding prevention and treatment interventions. ^{24 , 49 , 99 , 110} The guidelines can be implemented via print media and videos but supervision is required by trained mental health professionals. ⁸¹ Guidelines shared by national and international psychological associations can be utilized appropriately. ⁹⁸

Mass media including social media has a huge and important role in communicating timely and accurate information to the public, during an infectious disease epidemic, especially observed during COVID-19 pandemic. ¹¹¹ Appropriate spread of information by the government was found to be effective in decreasing the anxiety among public. ¹¹² However, information from the reliable sources ^{23 , 113} and avoiding excess social media exposure is also important. ⁵⁷

Providing clear communication even for follow-up information on changes in treatment modalities is the principal step in creating an environment devoid of panic and fear. ^{23 , 114} Ensuring timely and appropriate supplies of food, clothes, medicine and accommodation to remove any uncertainties in times of lockdown, quarantine and isolation were necessary. ^{23 , 24}

There is a need for alleviating the stigma associated with mental health disorders and infectious diseases itself because of which many individuals hesitate to get themselves screened. ¹¹¹ Mass media can play an important role in lessening the stigma and can pay attention to sensitive reporting. Some countries have released sensitive reporting guidelines. ¹¹¹ ii.

Developing mindfulness and resilience that can revive self-sufficiency and self-awareness in stress management:

This section is further divided based on population subgroup.

General population

Developing mindfulness ¹¹⁵ and psychological resilience were used as strategies during the COVID-19 pandemic. ¹¹⁵ There are many interventions e.g., e-interventions developed for improving self-sufficiency. One such e-intervention based on mindfulness, named ‘CoPE It’, has been ethically approved in Germany and its evaluation is ongoing. ¹¹⁶ Other coping mechanisms that can improve self-sufficiency were acceptance-based coping ¹¹⁷ and practicing self-compassion. ¹¹⁵

In order to protect oneself from mental health disorders, amidst infectious disease outbreaks, systematic psychological self-care can be practiced by indulging in mindfulness-based strategies. ¹¹⁷ These are the most convenient and economically viable methods to reduce stress among all populations. ¹¹⁸ Mindfulness-based strategies include physical activity, ^{43 , 99 , 110 , 113 , 117} yoga, ^{74 , 82} listening to music, ¹¹³ indulging in adequate sleep and stress management programs, ¹¹⁰ meditation, ^{74 , 82} and progressive muscle relaxation. ⁸² Additionally, mindfulness includes art-based interventions, ¹¹⁰ such as working on a hobby or engaging in creativity. ⁴³ Engagement in religious activities and keeping religious faith gives hope and can be an effective coping strategy. ^{51 , 56}

The approach to self-regulation ⁹⁷ can be achieved by having a routine ¹¹⁹ and control over the activity schedule. ¹¹⁵ This can be done with the help of digital wellbeing applications that help in keeping track of the daily routine and sleep. ¹¹³

A review of reviews carried among various population sub-groups demonstrated that self-guided therapies (e.g. mindfulness, cognitive-behavioral techniques, Acceptance and Commitment Therapy), positive psychology-based interventions (e.g. optimism, kindness or gratitude delivered via online or offline) and activity-based interventions (exercise) had small to medium effects in reducing depressive symptoms, anxiety and stress during isolation. ¹²⁰ Multi-component combination of online and app-based interventions had small to medium effects in reducing the common mental health disorders. ¹²⁰ Another review suggested that psychological therapy interventions (such as laughter therapy, Tai Chi Qigong meditation and mindfulness-based), social facilitation (facilitating interactions between peers) and befriending (making new friendship) interventions were effective in reducing loneliness. ¹²¹

People can be encouraged to foster strong interpersonal ties and compassion during these physically distant times. ¹¹⁵ There is a need for spending quality family time/support. ^{51 , 113 , 115} Keeping in touch with friends ^{113 , 115} through phone/video calls ^{57 , 97 , 104} and maintaining social networks through social media platforms ²³ may help in lessening the feeling of loneliness.

During an Ebola outbreak, survivors of the disease worked as volunteers to provide mental health support and creating awareness for the prevention and control of spread of infection, ¹²² while one group of survivors became advocacy providers to consultants and provided the information on challenges faced by survivors. ¹²³ 1.

Children and young people

Children require specific attention during epidemics, as their mental health wellbeing is affected as they are homebound with restricted outdoor activities. ^{87 , 109} Inculcating healthy lifestyle habits ⁵⁴ and having an activity schedule is advisable. Parents’ role in maintaining their children’s wellbeing, both physical and mental, is of great value during an epidemic. Engaging children in household chores to become independent, building healthy familial bonds, and practicing adaptive coping are important strategies. ^{87 , 109} Enrolling for online exercise classes (including dancing and singing) or support system would be helpful. ¹⁰⁹ Strategies such as semi-structured play activities, a short walk, LEGO-based therapy and online gaming can keep children occupied. However, these strategies should be implemented under the strict supervision of parents or caretakers. ¹¹⁹

Quarantined children can continue to have regular telephonic communication with parents for reassurance and support. ^{47 , 109} These children can receive educational and other important information ⁴⁷ via comics and videos. ⁸² Providing necessary and timely mental health support to children in quarantine ^{57 , 82 , 86 , 109} and educating children about normative reactions during COVID-19 ⁴⁷ are important strategies.

Online gaming is becoming common in keeping young people occupied especially during the COVID-19 pandemic. However, online gaming has its own repercussions such as excessive screen time and behavioral addictions. ^{99 , 124} A mixed methods study reported the beneficial effects of playing video games on the mental health of study participants. These video games were used for entertainment, medium to motivate, to remain physically active or as an escape mechanism/distraction. ¹²⁵ Therefore, balanced and healthy approach, ¹¹³ which is both physically engaging and socially interactive (such as exergames) can provide effective results to cope with psychological distress. ¹¹³ The WHO has extended its support to initiatives such as #PlayApartTogether to encourage online gaming and socializing. ⁹⁹

Underprivileged children are at increased risk of hunger, violence, abuse and exploitation thus increasing their vulnerability to anxiety, depression and suicide. Community volunteers, NGOs, and police can be involved in identifying these children, provide the psychological first aid, help in financial empowerment, and coordinate and refer to mental HCWs. ¹⁰⁹ 2.

Healthcare workers (HCWs)

HCWs are subjected to large amounts of stress and burnout during an infectious disease outbreak, leading to undiagnosed mental health problems that are often ignored. Encouragement and greater solidarity by colleagues can enhance the morale of the high-risk HCWs, working in infectious diseases wards, as was seen during SARS epidemic. ¹⁰⁵ Family and friends support via telecommunication act as a coping mechanism for common mental health disorders among HCWs. ^{71 , 105 , 126} Availability of protective gears was found to be assuring for the HCWs. ⁷¹

Self-coping strategies such as resilience, acceptance and active coping were found to be effective in controlling mental health disorders. Appropriate planning, behavioral disengagement, self-distraction, mindfulness and life adjustment such as indulging in physical activity and sleeping were self-coping strategies that were used by HCWs. ^{71 , 126} Earlier mindfulness-based interventions have proven to be effective to improve wellbeing of HCWs ¹²⁷ and potentially reduce stress among HCWs. ¹²⁸ Music therapy was found be effective among HCWs (who were quarantined in Italy during the COVID-19 pandemic) against anxiety and depression. ¹²⁹ Accessing mental health support such as counselling or psychotherapy ⁷¹ and insurance and compensation related facility were found to be effective in reducing the mental health disorders among HCWs. ^{71 , 126}

Implementation of workplace interventions were influenced by HCW or organization’s lack of awareness on their own mental health support needs and a lack of equipment, staff time or skills needed for an intervention. ¹³⁰ While strategies that were customized for local needs; with effective communication, both formally and socially; and with positive, safe and supportive learning environments for frontline workers facilitated workplace intervention implementation. ¹³⁰ 3.

Older adults

Special attention should be given to psychosocial support and an interpersonal inventory ¹⁰⁴ for older adults. Friends, neighbors, volunteers or peers can come forward to help older adults to help overcome social isolation and provide mental health support. A previously conducted systematic review among older adults demonstrated acceptability, feasibility and effectiveness of telemedicine interventions for mental health care. ¹³¹ 4.

COVID-19 positive individuals

A meta-analysis based on the studies conducted in China, found that non-pharmacological interventions (such as alterations in COVID-19 appropriate behaviors, hospital-based prevention control measures and modification of the home-based environment) were effective in reducing the anxiety (SMD: -1.40, 95%CI: -1.62, –1.17), and depression (SMD: -1.22, 95% CI: -2.01, -0.43) ¹³² among COVID-19 positive individuals. iii.

Early identification, providing necessary mental health care and treatment through professionals:

During an outbreak, individuals with pre-existing mental health conditions, older adults, people with substance abuse where the condition is exacerbated, and in certain cases the general population, need urgent intervention by a medical practitioner.

Population screening can be employed to identify high-risk groups to address their needs ^{50 , 98} and make possible early recognition of mental health disorders, ²⁴ including subclinical or minor disorders. ¹¹¹ Wherever possible, online surveys can be conducted to screen people in need. ⁶⁴ HCWs can practice empathy, provide person-centered care and regular assessment of the psychological symptoms while managing delirium in patients hospitalized in intensive care units. ¹⁰⁴

Upon identification of mental health disorders, counselling and referral can be advised. Counselling and treatment can be ascertained through digital medium via video calls and e-consultation ^{46 , 100} . The COVID-19 pandemic has paved a way for widespread use of digital psychiatry ^{101 , 111} , digital interventions ^{100 , 110 , 133} , virtual care/web-based counselling, ^{51 , 56 , 64 , 72 , 75 , 87 , 98 , 111 , 119 , 134} at-home neuro-therapeutics and self-administered brain stimulation. ⁹⁴

Smartphone based e-interventions are useful in delivering tele-health consultation, ^{83 , 113 , 134} and more specifically telemedicine ^{64 , 73 , 133} and tele-psychiatry emergency services. ^{73 , 76 , 135} Therapy-derived interventions such as CBT, mindfulness-based interventions, Acceptance and Commitment Therapy were found to be mild to moderate effective in lowering stress, anxiety and depression. ¹²⁰ iv.

Health system strengthening and capacity building:

Individuals living in low- and middle-income countries are facing shortage of mental health resources such as trained manpower and infrastructure. For example, in India currently there is one psychiatrist for more than 125,000 individuals, whereas the ideal ratio should have been at least 1:8000. ¹¹¹ A similar situation can be found in other countries belonging to the global south. There is an immediate need for capacity building of primary health care professionals in mental health care and for solidarity and cooperation between private, government, NGOs and other philanthropic organizations to address the mental health assistance and support. ¹¹¹

Lately, due to the second wave of the COVID-19 pandemic, South Asian countries specifically India, faced a mammoth public health crisis. With overburdened health systems and inaccessibility to primary health care, the impact of the COVID-19 second wave was devastating in these countries. In this scenario, and since the entire world is experiencing or expecting a third wave of the pandemic, the importance of providing adequate interventions for both short-term and long-term common mental health disorders should be a priority. Based on our review findings, we have tried to propose few recommendations: a.

Information education and communication via use of mass media:

We conducted a comprehensive search in five major databases, therefore we anticipate that we have captured most of the literature. However, this review has some limitations. Randomized controlled trials provides strong evidence of effective interventions but are not feasible options in public health emergencies. Also, the studies that were included in the systematic review were heterogeneous and some studies collected data via online surveys. Additionally, the search was restricted to English publications. Due to limited availability of evidence on effectiveness of interventions, we could not synthesize the most effective interventions, rather have summarized it thematically. We did not independently screen full texts, extracted data and have not critically appraised the included studies for the risk of bias. Considering aforementioned limitations, we call for urgent high-quality research to find the most effective interventions for the psychological problems amidst infectious disease outbreaks so that it can be translated into action to tackle these issues during COVID-19 and in future emerging and re-emerging infectious disease illness.