There has not been an infectious disease outbreak similar to the COVID-19 pandemic in recent history. However, by reviewing literature from outbreaks in the past such as the SARS CoV-1, MERS, Ebola, the Anthrax threat in the U.S., and various natural disasters, it is possible to propose what might happen based on similar events in the past.
SARS CoV-1
The SARS CoV-1 was first reported in Asia in 2003, spreading to countries in North America, South America, Europe, and Asia, infecting more than 8000 people as described by the Centers for Disease Control [17].
A few studies regarding healthcare worker’s experiences following SARS CoV-1 have been reported. Healthcare workers represent a unique group of people who have experienced numerous stressful events throughout the pandemic. While there may not be a clinical psychiatric diagnosis that manifests, it is important to identify post-traumatic stress symptoms, and increased health risk behaviors such as alcohol and tobacco use [18]. Three years after the SARS CoV-1 outbreak in Beijing, it was found that among certain subcategories of health care workers, there were higher mean alcohol abuse/dependence symptoms [18]. These subcategories included men ages 36–50, lower educational levels, upper-middle level family income levels, those who worked in units with high levels of exposure, and those who had been quarantined [18].
In addition to increased alcohol abuse/dependence in healthcare workers, it might also be important to screen for depressive symptoms [19]. Following the SARS CoV-1 outbreak having been quarantined and pre-SARS trauma exposure were predictors of high levels of depressive symptoms three years after the outbreak [19]. While specific groups of healthcare workers may be affected differently during this pandemic, this highlights the long-term effects the COVID-19 pandemic is likely to have on healthcare workers.
MERS
In 2015 there was an outbreak of Middle Eastern Respiratory Syndrome (MERS) in Korea resulting in a 20% mortality rate [20]. Much like COVID-19, preventive vaccine and treatment options were not clearly established. During the MERS epidemic 80.2% of the general public reported fear of being infected, and 46% reported emotional distress [21]. Risk factors associated with the fear among the general public included public transportation use, difficulty going outside, perception that the state is not protecting people, helplessness in situations that cannot be controlled, and fear of infection [21]. In many ways the nature of the MERS epidemic was similar to the COVID-19 pandemic in the sense that fear of being infected and many of the risk factors contributing to that fear are felt today.
Anxiety and anger are two emotions commonly expressed in times of uncertainty. MERS patients and those thought to have come in contact with MERS patients isolated for an average of two weeks. During isolation, 47.2% of MERS patients reported symptoms of anxiety, and 19.4% reported these symptoms persisted 4 to 6 months later [21]. This represents the lasting effects that experience anxiety can have on people during isolation.
Anger, as a temporary feeling, was also assessed in those without anger disorders [21]. During isolation, 16.6% of individuals who were isolated and 28.1% of MERS patients who were isolated reported persistent anger four to six months later [21]. With the similarities between the MERS epidemic and the COVID-19 pandemic, this information can be useful in how we assess individuals during and after isolation. It is important to identify symptoms of anxiety, anger and aggression during and after isolation and quarantine to prevent these symptoms from evolving into long-term PTSD.
Ebola
The Ebola outbreak in 2014, with the virus’ highly infectious and virulent nature, rapid progression, and high fatality rate resulted in extraordinary levels of fear [22]. Heightened anxiety throughout the United States was experienced indirectly through ongoing and widespread media coverage of the few cases of Ebola reported in the United States. The Ebola outbreak developed as a “contagion of fear” representing behavioral health effects that are not directly related to or limited by the proximity to the infectious outbreak [22]. Resulting fear-based decisions to quarantine, against medical advice, may have influenced the general public’s distrust, as well as increasing confusion and anxiety.
Anthrax Threat
In 2001, following the 9/11 terrorist attacks, the U.S. experienced its first bioterrorism incident. Letters filled with anthrax were delivered to political officials on Capitol Hill. While bioterrorism is different in many ways from an epidemic, the psychological distress is similar. Much like the effects of COVID-19, the magnitude and effect of the anthrax attacks were delayed and uncertain. This uncertainty commonly leads to fear and can manifest and exacerbate mental instability and illnesses. The anthrax threat demonstrated a time that stress was not only experienced by those directly exposed, but also in those that believed they were exposed [23]. Individuals who incorrectly believed they were exposed, were shown to be at increased risk of being very upset, losing trust in health authorities, and having concerns about mortality [23]. Losing trust in health authorities is an important implication that should be identified early. During an outbreak trusting and following recommendations set by healthcare officials is the way that the outbreak is controlled. The risk of individuals changing their healthcare behavior based on distrust in authorities is an important risk that can be translated to the COVID-19 pandemic. Whether an individual was exposed or not, the beliefs about their exposure may be a more powerful predictor of mental health outcomes [23]. With constantly changing and differing policies between countries and states surrounding COVID-19, steps taken to control the spread of disease, and the vast amount of misinformation distributed among the general public, the belief of exposure is likely to widely vary among individuals.
Natural Disasters
While pandemics represent a unique form of natural disaster resulting in both adverse psychological and behavioral responses, the psychological effects of natural disasters represent another area that can be investigated to conclude how human behavior changes in response to disasters and crises.
Natural disasters commonly result in distress reactions, increased health risk behaviors, and exacerbation or manifestation of psychiatric disorders [22]. The psychological effects of natural disasters can last for a significant period of time. Following the Wenchuan earthquake in 2008, 38.3% of adolescents reported sleep disturbances 12 months after the event with no significant reduction at 24 months after the event [22]. Because sleep is an integral part of physical and mental health, the lasting effects that this natural disaster had on adolescent’s sleep represents a distress reaction that increases the risk of developing mental and physical health problems in the future.
The Japan triple disaster, on March 11, 2011 in which an earthquake, tsunami, and a meltdown at a nuclear power plant represented a severe natural disaster [24]. A study assessing health risk behaviors following the event identified a significant increase in alcohol use following the disaster [25]. In this study out of 37,867 individuals who did not drink prior to the Japan triple disaster, 9.6% reported drinking in 2012, and 53.8% reported continued drinking in 2013 [25]. This is an example of health risk behaviors that may be long lasting following a crisis. Similar to decreased sleep, increased alcohol use over time can have deleterious effects on the mind and body.
Another high-risk group of people who might experience long term effects of the experiences surrounding the pandemic are children. Experiencing a natural disaster by age 5 has been shown to significantly increase the risk of mental health and substance use disorders in adults [26]. In addition to the direct experience of the natural disaster, this response is also likely due to changing parenting styles [26]. Parenting styles during natural disasters demonstrated increases in maltreatment behaviors and emotional support [26]. This highlights the importance of identifying children and parents that may be experiencing greater amounts of stress or are unable to cope with new stressors.
While there are many different aspects to how an infectious disease outbreak and a natural disaster affect mental health, there are also similarities. An abrupt change in daily life, a sense of uncertainty about the future, resource limitations, fear for personal well-being, increased use of media and spread of misinformation represent a few of the similar experiences felt during a pandemic and natural disaster.
Anticipated Psychiatric Effects of COVID-19
In the last week of March 2020, there were over 3 million unemployment claims in the U.S [27]. In addition to the fear and uncertainty surrounding control of the spread of disease; unemployment; potential threat to meeting physiological needs of self and loved ones; and the numerous other biopsychosocial stressors experienced are all likely to pose a threat to mental well-being. This can manifest as acute exacerbations of known disorders in stable patients, new onset of mental disorders in vulnerable patients, stressor-related disorders, and a host of other psychiatric symptoms. This is likely to necessitate a system-readiness for providing psychological support and for making sure that appropriate resources to provide evidence-based interventions are in place.
One of the widespread methods to control spread of disease during the COVID-19 outbreak is the use of quarantine. A review published on the psychological impact of quarantine in past pandemics identified resulting post-traumatic stress symptoms, confusion, and anger as commonly experienced negative psychological effects [28]. Stressors during quarantine included infection fear, frustration, boredom, inadequate supplies, inadequate information, financial loss, stigma, and increasing quarantine duration [28]. The numerous psychological effects and additional stressors demonstrated by past quarantines are likely to reappear.
While the psychological distress during and following COVID-19 is an enormous threat to mental well-being in communities across the globe, the human central nervous system may also be directly affected by the immunologic response of the virus itself [29]. While neuropsychiatric sequelae may only be experienced by a fraction of cases, given the global burden of COVID-19 infection the implications of any delayed complication will be significant. With neuropsychiatric symptoms as a result of viral infection in the past being noted, they have largely been unexplored. Troyer et, al. suggest that the psychoneuroimmunology perspective following the COVID-19 pandemic will be an important aspect in the developing effects of the current pandemic [29].