Mental Health: Pandemics, Epidemics and Tau Protein

Ghinwa M. Barakat1, Ghaith Assi2, Noura B. El Khoury1, *
1 Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon
2 Department of Neuroscience, Gilbert and Rose-Marie Chagoury School of Medicine, Lebanese American University, Beirut, Lebanon

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© 2023 Barakat et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon; E-mail:



It is well established that a wide range of psychological disorders are influenced by the way people live, with lifestyle-related factors playing a substantial role. During the past decade, the effects of major disasters on mental health have drawn a lot of attention.


In this review, we compare clinical studies reporting a link between COVID-19 and other pandemics and mental health. Importantly, we also shed light on Tau protein and neurotransmitters as neurobiological factors that might explain this link.


Athorough PubMed search was done to gather and summarize published data on the COVID-19 pandemic’s effect on mental health. Additionally, these studies were compared to previous research published on PubMed, triggering other pandemic and epidemic impacts on mental health.


The COVID-19 epidemic has had the biggest impact on raising awareness about mental health. Moreover, the past century has seen an increase in the frequency of disease outbreaks like MERS-CoV, Ebola, and Influenza, which all had an impact on mental health. However, the exact role of these epidemics on mental health and brain functions is poorly understood.


Future research on the underlying pathways may yield essential information for the treatment and prevention of prospective mental diseases in light of the ongoing decline in mental health during the past 10 years.

Keywords: Mental health, Depression, Anxiety, PTSD, COVID-19, Pandemics/Epidemics, Tau, Neurotransmitters.


1.1. Mental Health: Then and Now

Different systems, cultures, or therapeutic practices have different ideas about what constitutes mental and social health [1]. According to World Health Organization, mental health is a condition of well-being in which a person is aware of their own potential, able to deal with everyday stressors, capable of productive and fruitful employment, and able to give back to their community [2]. According to this concept, having a healthy mental state requires more than just the absence of mental disorders [3]. Hence, modern clinical psychiatry now places a strong emphasis on preventing mental illnesses. The indicated prevention of mental diseases lowers subthreshold symptoms in those who are at risk, which will ultimately result in a reduction in the prevalence and incidence of mental disorders [4]. However, these prevention strategies are insufficient because they typically do not aim to reach the entire population [5]. Moreover, the focus on medical disease has dominated that of clinical psychiatry for the past several decades [6]. For this reason, research efforts in the mental health area have been irregular and inconsistent [7]. Nevertheless, following the rapid increase in mental health issues and especially after COVID-19 pandemic, this topic is witnessing a revival and reconsideration.

1.2. Mental Health: The Player-makers

Numerous psychological conditions are known to be caused or affected by how people live, with related lifestyle variables having a significant role in this. For instance, many epidemiological studies have revealed that lifestyle elements, including nutrition, exercise, mental activity, and stress have a big impact on how long people can live with a healthy mentality [8]. These factors can have either a negative or a positive effect.

For instance, Obesity, which has been increasing dramatically over the past 70 years [9], has contributed to an increase in metabolic diseases like type 2 diabetes, which has been linked to psychiatric disorders like depression [10].

The body of studies supporting the improvement and prevention of psychiatric diseases through altering certain lifestyle factors is steadily expanding [11]. For example, smoking has been proven to significantly increase the risk of morbidity and mortality through the emergence of numerous cancers and other illnesses. This, in turn, have a detrimental effect on mental health [12]. A study reported that smokers experienced higher drop-out rates, greater mental discomfort, and worse quality of life from the start to a six-month follow-up period as compared to non-smokers [13].

Another study showed that exercise plays a positive major role on mental health in particular mood states such as anxiety, depression, and stress through different body mechanisms [14]. For example, it was reported that exercise improved mental health and reduced the need of care in schizophrenic patients [15].

Although social connections typically play a positive function on an individual’s mental health, their protectiveness differs between groups and sexes. Men and women seem to receive different kinds of social support from social networks [16]. Yet, given the evolving complexity of human interactions, it is oversimplified to assume that everyone, regardless of age, gender, educational attainment, social status, and cultural background, will benefit from increased social networking, especially online [17].

1.3. Mental Health: Disasters Aftermath

The consequences of significant disasters on mental health have received a lot of attention. There is a sizable and quickly expanding body of research on the effects of disasters on affected populations' mental health. PTSD (Post-Traumatic Stress Disorder) is typically reported to be the most prevalent disorder in populations exposed to disasters and has historically been the disorder associated with catastrophes that have been studied the most [18]. Following exposure to trauma, psychiatric comorbidity with PTSD is quite common, especially major depressive disorder and substance abuse [19]. This agrees with most disaster research that has shown major depression as the second most common post-disaster disorder [20]. Moreover, alcohol and drug use have been found to increase following disasters, according to research on the topic [21]. For additional post-disaster psychiatric diseases such as generalized anxiety disorder, panic disorder, and adjustment disorder, relatively fewer studies have provided prevalence data. In these studies, the prevalence rates of these diseases are typically much lower than those for PTSD and major depression [22]. COVID-19 (Corona Virus Disease-19), being a health “disaster” or crisis, would also trigger the curiosity to research its impact on mental health. Not only this, but it would also prompt an interest in relating biological factors to mental health.

1.3.1. Aim

In this review, we discuss the impact of the COVID-19 pandemic compared to other previous pandemics and shed light on the Tau protein and neurotransmitters as neurobiological factors that play a role in mental health.


A thorough PubMed search was done to gather and summarize published data on the COVID-19 pandemic’s effect on mental health. Additionally, these studies were compared to previous research published on PubMed on other pandemic and epidemic impacts on mental health.


3.1. COVID-19: Quarantine and Mental Health

The contagious illness COVID-19 is brought on by the SARS-CoV-2 virus. The COVID-19 outbreak was accomp- anied by a drop in positive emotions and life content among the general public, as well as an immediate rise in negative emotions, including anxiety and depression [23]. For instance, according to a study conducted in Wuhan, 20% of Wuhan students who were required to stay at home reported experiencing anxiety and depression [24]. The long-term psychiatric effects of COVID-19 are probably similar to those seen during the SARS (Severe Acute Respiratory System) outbreak (which started in February 2003 and lasted for six months), so that after physical recovery, 50% and 20% of survivors continued to show signs of anxiety and depression, respectively, and people who were given antiviral and corticosteroid medications also showed strong memory problems [25]. Additionally, it appeared that the psychological discomfort in quarantine settings, like social distancing or isolation, was adversely related to the advised health behaviors to reduce the chance of infection [26].

According to a recent analysis of the effects of quarantine and similar preventive measures on mental health, people who have experienced physical isolation are much more likely to experience depression, anxiety disorders, mood disorders, sleep disorders, panic attacks, posttraumatic stress symptoms, stigmatization, low self-esteem, and a lack of self-control [27].

A study conducted by Wang and his colleagues showed that a moderate to severe mental health concern, such as signs of depression, anxiety, insomnia, or acute stress, was reported by 29.2% of the 56,679 participants from 34 Chinese provinces [28].

Another quick examination revealed that widespread posttraumatic stress symptoms, disorientation, and anger might have been brought on by stressors such as extended quarantine, fear of infection, annoyance, boredom, insufficient supplies, poor information, financial loss, and stigma [29].

3.2. COVID-19: Previous Diseases and Mental Health

Another issue with regard to global health is how COVID-19 psychologically affects people who test positive [30]. Patients with previous diseases or those with poor access to healthcare are more likely to experience psychological stress during this epidemic [31]. Additionally, prior to the pandemic, some individuals and populations may have experienced a number of mental health issues [32], which could make them more vulnerable to negative mental health outcomes after receiving a COVID-19 diagnosis. There is even more research indicating that COVID-19 patients may experience depression, anxiety disorders, psychological distress, and suicidal behavior [33], which calls for a thorough study of the mental health epidemiology during this pandemic. A study revealed that changes in distress caused by COVID-19 were explained by changes in the severity of the coronavirus symptoms; distress was more prominent in individuals whose symptoms were more severe and took longer to go away [34]. Moreover, according to the research conducted by Xie and his colleagues, those who survive the acute stage of COVID-19 are more likely to experience a variety of incident mental health conditions [35]. Combating mental health issues among COVID-19 survivors needs to be a top concern. Not to mention the increased suicide rates, which must also be taken into account [36]. Suicide rates appear to be linked to the effects of the lockdown-related economic slowdown, such as unemployment and fear of infection, especially in low-income nations [37].

3.3. COVID-19: Front Liners and Mental Health

It is also worth mentioning that COVID-19 may also have an impact on the healthcare personnel’s mental health and general wellness, particularly those who serve as frontline providers [38]. An increase in working hours for many healthcare workers that are needed to address the increasing demand for critical care as COVID-19 cases have an impact on the capacities of health systems around the world. These factors were shown to increase the risk of anxiety, sadness, burnout, and insomnia [39]. In an Italian study of oncology specialists, the majority of whom were doctors, 69.2% of the participants reported deteriorating mood, 92% reported concerns about the virus, and 59.5% revealed anxiety over postponing cancer patients' therapies [40]. Moreover, depression symptoms considerably rose during the pandemic compared to pre-pandemic levels, according to a study that looked at doctors in China prior to COVID-19 (2018-2019) and during the pandemic (2019-2020) [41]. Not to mention, in Saudi Arabia, during COVID-19, 56.9% of physicians reported feeling isolated [42].


Population growth, the world's growing interconnection, microbiological adaptation and change, economic develop- ment, changes in land use, and climate change have all contributed to a rise in the frequency of disease outbreaks during the past century. Hence, COVID-19 is not the only pandemic, but it is one of the many that also had a great impact on the population’s mental health. For instance, during the MERS-CoV epidemic, compared to individuals who had not been exposed, nurses who had been exposed to confirmed or suspected MERS cases showed a higher level of stress [43]. In addition, higher degrees of anxiety were reported by non-physicians about the possibility of spreading MERS-CoV to their family [44].

This case was not different during the Ebola epidemic, as healthcare workers (HCWs) in all three of the impacted countries, as well as Ebola survivors in Guinea and Sierra Leone, have all been shown to be in very high levels of distress [45]. Moreover, after a year of the Ebola response, PTSD and anxiety-depression symptoms were widespread, and those who had Ebola-related experiences could require psychosocial care [46].

This is also the case during influenza epidemics, where, in contrast to bipolar disorder, case-control research reported that people who were exposed to an influenza epidemic during the second trimester of fetal development are more likely to acquire unipolar affective disorders, which supports the neuro-developmental concept of the affective disorder [47]. This means that the epidemic had only depressive episodes without any manic ones, which were shown to be linked to neurodevelopment. Yet, compared to employees working in low-risk environments, those in high-risk workplaces were more stressed and exhausted during the H1N1 epidemic [48].

Table 1. Epidemics and Pandemics: Studies on their effects in different targeted populations.
Pandemic (P)/Epidemic(E) Year of Study Type of Mental Disorder Affected People Results
MERS-CoV (E) 2017 Stress Nurses “When compared to individuals who had not been exposed, the nurses that had been exposed to confirmed or suspected MERS cases showed a higher level of stress.”
MERS-CoV (E) 2019 Anxiety Non-physicians “Higher degrees of anxiety were reported by non-physicians about the possibility of spreading MERS-CoV to their family.”
Ebola (E) 2017 Distress Health Care Workers “Healthcare workers (HCWs) in all three of the impacted countries, as well as Ebola survivors in Guinea and Sierra Leone, have all been shown to be in very high levels of distress.”
Ebola (E) 2018 PTSD
Population in affected countries “After a year of the Ebola response, PTSD and anxiety-depression symptoms were widespread, and those who had Ebola-related experiences may require psychosocial care.”
Influenza (E) 1997 Unipolar affective
Exposed population “The people who were exposed to an influenza epidemic during the second trimester of their fetal development are more likely to acquire unipolar affective disorders, which supports the neuro-developmental concept of affective disorder.”
Influenza (H1N1) (E) 2012 Stress High-risk workplaces “High-risk workplaces had more stressed and exhausted personnel during the H1N1 epidemic.”
SARS (P) 2005 PTSD SARS patients “SARS patients typically experienced post-traumatic stress disorder (PTSD) while recovering.”
SARS (P) 2006 Psychological
SARS survivors “41–65% of SARS survivors had persisting psychological symptoms.”
SARS (P) 2007 PTSD SARS patients who were healthcare workers “SARS patients who were healthcare workers are at an elevated risk of PTSD (40.7%).”
SARS (P) 2006 Distress Health professionals who treated SARS patients “Health professionals who treated SARS patients but were not infected continued to experience significant psychological distress”

On the other hand, SARS patients typically experience post-traumatic stress disorder (PTSD) while recovering, with one study finding that the lowest blood oxygen saturation (SaO2) level during hospitalization was the most important predictor for intrusion and avoidance symptoms [49]. It is also significant to highlight that, although earlier investigations were not intended to make a psychiatric disease diagnosis, they revealed that 41–65% of SARS survivors had persisting psychological symptoms [50]. The finding that SARS patients who were healthcare workers are at an elevated risk of PTSD (40.7%) is also in line with a prior study's findings [51], as well as the discovery that health professionals who treated SARS patients but were not infected continued to experience significant psychological distress [52] (Table 1).


Although a large number of studies have investigated the role of epidemics on mental health, the neurological mechanisms underlying this relationship are still poorly understood. Tau is a microtubule-associated protein (MAP) expressed in neurons. Its function is to regulate the normal operation of the cytoskeletal network in terms of microtubule assembly [53]. Importantly, the most prevalent form of dementia is Alzheimer's Disease (AD), a chronic neurodegenerative condition [54]. Two key characteristics of AD include the extracellular buildup of amyloid-beta (Aβ) peptides as amyloid plaques and the formation of intraneuronal neurofibrillary tangles (NFTs) from hyperphosphorylated or abnormally phosphorylated Tau protein [55]. The presence of NFTs is a characteristic of a group of degenerative diseases known as Tauopathies [56].

In addition to its contribution to AD, Tau was shown to play a role in mental health disorders. For example, in one imaging study, it was reported that depression was twice as likely to be present in participants with elevated Tau. Similarly, participants with increased Tau who were taking antidepressants had a higher likelihood of experiencing depression [57]. Moreover, in another study, increased Tau binding on PET was found to be significantly linked with cognitive impairment in the PTSD (Post Traumatic Stress Disorder) population [58].

Interestingly, postmortem studies also reported a link between Tau hyperphosphorylation and mental health. For example, a recent study reported the presence of hyper-phosphorylated Tau in the postmortem brains of bipolar patients [59] at the Thr231 site, which is known to be important in microtubule assembly and stabilization [60]. Therefore, this will affect major cellular mechanisms such as axonal transport and neuronal differentiation [61]. Moreover, it was reported that patients with schizophrenia had considerably lower blood total Tau and phosphorylated Tau levels in comparison to healthy controls [62]. Further studies are needed in this context, as Tau peripheral levels could be different from those in the brain.

It is important to mention that some studies focused on metals’ role in neurodegeneration. Four metal ions (Al, Zn, Fe, and Cu) may have diverse effects on the development of amyloid aggregates [63]. For instance, amyloid protein precursors are copper-binding proteins [64]. Metal ions may impact the aggregation of amyloid beta (Aβ) monomers from random coil Aβ monomers to beta-sheet monomers, resulting in the production of mature fibrils that eventually settle as senile plaques [65].


The onset and progression of depression and anxiety were tightly correlated with the central nervous system's neurotransmitter alterations [66]. Through meta-analysis, Romeo and his associates demonstrated that patients with major depressive disorder (MDD) have lower GABA expression levels in their brains and peripheral tissue [67]. Moreover, numerous neuropsychiatric conditions were linked to dopamine and its receptor abnormalities, which also contributed to the development of depression [68]. Also, depression and serotonin levels in the brain were proven to be intimately connected [69]. There are reports from a study conducted by Hermann and his team supporting norepinephrine's involvement in dementia due to the loss of noradrenergic neurons in Locus Coeruleus (LC) [70], and it has also been discovered by Mathews and his colleagues that variations in this neurotransmitter's typical function are linked to AD [71]. Moreover, in the CNS, astrocytes are the primary sites of viral infection, according to a new post-mortem analysis, and cells infected with SARS-CoV-2 show noticeable metabolic alterations [72]. However, the restoration of the glial physiological state, whether by the astrocytes or even the microglial cells, may not take place in some individuals. This, in turn, compromises glial function and ultimately leads to homeostatic failure, which underlies a specific set of neuropsychiatric symptoms associated with COVID-19 [73].


In conclusion, several clinical studies have found a link between mental health disorders and pandemics or epidemics, such as COVID-19, ebola, and influenza. Although the link is still poorly understood, studies converge to indicate that Tau hyperphosphorylation and neurotransmitter imbalance might represent possible neurological mechanisms. In light of the continuous decline in mental health over the last decade, future focus on the underlying mechanisms may provide invaluable information for the treatment and prevention of potential mental disorders.


All authors contributed equally to this work. All authors read and approved the final manuscript.


PTSD = Post- traumatic Stress Disorder
AD = Alzheimer's Disease
= Amyloid-beta
MDD = Major Depressive Disorder
NFTs = Neurofibrillary Tangles


Not applicable.


The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.




The authors declare that they have no conflict of interest related to the manuscript.


Declared none.


[1] Manwell LA, Barbic SP, Roberts K, et al. What is mental health? Evidence towards a new definition from a mixed methods multidisciplinary international survey. BMJ Open 2015; 5(6): e007079.
[2] World Health Organization. Prevention of mental disorders: Effective interventions and policy options. 2004. Available from:
[3] Fusar-Poli P, Salazar de Pablo G, De Micheli A, et al. What is good mental health? A scoping review. European neuropsychopharmacology 2020; 31: 33-46.
[4] Shatkin JP. Mental health promotion and disease prevention: It’s about time. J Am Acad Child Adolesc Psychiatry 2019; 58(5): 474-7.
[5] Keyes CLM, Dhingra SS, Simoes EJ. Change in level of positive mental health as a predictor of future risk of mental illness. Am J Public Health 2010; 100(12): 2366-71.
[6] Arango C, Díaz-Caneja CM, McGorry PD, et al. Preventive strategies for mental health. Lancet Psychiatry 2018; 5(7): 591-604.
[7] Snodgrass JG, Lacy MG, Upadhyay C. Developing culturally sensitive affect scales for global mental health research and practice: Emotional balance, not named syndromes, in Indian Adivasi subjective well-being. Soc Sci Med 2017; 187: 174-83.
[8] Li Y, Pan A, Wang DD, et al. Impact of healthy lifestyle factors on life expectancies in the US population. Circulation 2018; 138(4): 345-55.
[9] Caballero B. The global epidemic of obesity: An overview. Epidemiol Rev 2007; 29(1): 1-5.
[10] Stuart MJ, Baune BT. Depression and type 2 diabetes: Inflammatory mechanisms of a psychoneuroendocrine co-morbidity. Neurosci Biobehav Rev 2012; 36(1): 658-76.
[11] Cotman CW, Berchtold NC, Christie LA. Exercise builds brain health: Key roles of growth factor cascades and inflammation. Trends Neurosci 2007; 30(9): 464-72.
[12] Aras YG, Tunç A, Güngen BD, Güngen AC, Aydemir Y, Demiyürek BE. The effects of depression, anxiety and sleep disturbances on cognitive impairment in patients with chronic obstructive pulmonary disease. Cogn Neurodynamics 2017; 11(6): 565-71.
[13] Lien L, Bolstad I, Bramness JG. Smoking among inpatients in treatment for substance use disorders: Prevalence and effect on mental health and quality of life. BMC Psychiatry 2021; 21(1): 244.
[14] Mikkelsen K, Stojanovska L, Polenakovic M, Bosevski M, Apostolopoulos V. Exercise and mental health. Maturitas 2017; 106: 48-56.
[15] Scheewe TW, Backx FJG, Takken T, et al. Exercise therapy improves mental and physical health in schizophrenia: A randomised controlled trial. Acta Psychiatr Scand 2013; 127(6): 464-73.
[16] Kawachi I, Berkman LF. Social ties and mental health. J Urban Health 2001; 78(3): 458-67.
[17] Pantic I. Online social networking and mental health. Cyberpsychol Behav Soc Netw 2014; 17(10): 652-7.
[18] North CS, Hong BA, Pfefferbaum B. P-FLASH: Development of an empirically-based post-9/11 disaster mental health training program. Mo Med 2008; 105(1): 62-6.
[19] Foa EB, Stein DJ, McFarlane AC. Symptomatology and psychopathology of mental health problems after disaster. J Clin Psychiatry 2006; 67(Suppl. 2): 15-25.
[20] Norris FH, Friedman MJ, Watson PJ, Byrne CM, Diaz E, Kaniasty K. 60,000 disaster victims speak: Part I. An empirical review of the empirical literature, 1981-2001. Psychiatry 2002; 65(3): 207-39.
[21] Boscarino JA, Adams RE, Galea S. Alcohol use in New York after the terrorist attacks: A study of the effects of psychological trauma on drinking behavior. Addict Behav 2006; 31(4): 606-21.
[22] North CS, Oliver J, Pandya A. Examining a comprehensive model of disaster-related posttraumatic stress disorder in systematically studied survivors of 10 disasters. Am J Public Health 2012; 102(10): e40-8.
[23] Li S, Wang Y, Xue J, Zhao N, Zhu T. The Impact of COVID-19 epidemic declaration on psychological consequences: A study on active weibo users. Int J Environ Res Public Health 2020; 17(6): 2032.
[24] Xie X, Xue Q, Zhou Y, et al. Mental health status among children in home confinement during the coronavirus disease 2019 outbreak in Hubei Province, China. JAMA Pediatr 2020; 174(9): 898-900.
[25] Tsang HW, Scudds RJ, Chan EY. Psychosocial impact of SARS. Emerg Infect Dis 2004; 10(7): 1326-7.
[26] Ben-Ezra M, Sun S, Hou WK, Goodwin R. The association of being in quarantine and related COVID-19 recommended and non-recommended behaviors with psychological distress in Chinese population. J Affect Disord 2020; 275: 66-8.
[27] Hossain MM, Sultana A, Purohit N. Mental health outcomes of quarantine and isolation for infection prevention: A systematic umbrella review of the global evidence. Epidemiol Health 2020; 42: e2020038.
[28] Wang Y, Shi L, Que J, et al. The impact of quarantine on mental health status among general population in China during the COVID-19 pandemic. Mol Psychiatry 2021; 26(9): 4813-22.
[29] Brooks SK, Webster RK, Smith LE, et al. The psychological impact of quarantine and how to reduce it: Rapid review of the evidence. Lancet 2020; 395(10227): 912-20.
[30] Zhou SJ, Zhang LG, Wang LL, et al. Prevalence and socio-demographic correlates of psychological health problems in Chinese adolescents during the outbreak of COVID-19. Eur Child Adolesc Psychiatry 2020; 29(6): 749-58.
[31] Kavoor AR. COVID-19 in people with mental illness: Challenges and vulnerabilities. Asian J Psychiatr 2020; 51: 102051.
[32] Hossain MM, Khan N, Sultana A, et al. Prevalence of comorbid psychiatric disorders among people with autism spectrum disorder: An umbrella review of systematic reviews and meta-analyses. Psychiatry Res 2020; 287: 112922.
[33] Rogers JP, Chesney E, Oliver D, et al. Psychiatric and neuropsychiatric presentations associated with severe coronavirus infections: a systematic review and meta-analysis with comparison to the COVID-19 pandemic. Lancet Psychiatry 2020; 7(7): 611-27.
[34] Daly M, Robinson E. Acute and longer-term psychological distress associated with testing positive for COVID-19: longitudinal evidence from a population-based study of US adults. Psychol Med 2021; 1-8.
[35] Xie Y, Xu E, Al-Aly Z. Risks of mental health outcomes in people with COVID-19: Cohort study. BMJ 2022; 376: e068993.
[36] Lennon JC. What lies ahead: Elevated concerns for the ongoing suicide pandemic. Psychol Trauma 2020; 12(S1): S118-9.
[37] Mamun MA, Ullah I. COVID-19 suicides in Pakistan, dying off not COVID-19 fear but poverty? – The forthcoming economic challenges for a developing country. Brain Behav Immun 2020; 87: 163-6.
[38] Li G, Miao J, Wang H, et al. Psychological impact on women health workers involved in COVID-19 outbreak in Wuhan: a cross-sectional study. J Neurol Neurosurg Psychiatry 2020; 91(8): 895-7.
[39] Pappa S, Ntella V, Giannakas T, Giannakoulis VG, Papoutsi E, Katsaounou P. Prevalence of depression, anxiety, and insomnia among healthcare workers during the COVID-19 pandemic: A systematic review and meta-analysis. Brain Behav Immun 2020; 88: 901-7.
[40] Ballatore Z, Bastianelli L, Merloni F, et al. Scientia Potentia Est: How the Italian world of oncology changes in the COVID-19 pandemic. JCO Glob Oncol 2020; 6(6): 1017-23.
[41] Li W, Frank E, Zhao Z, et al. Mental Health of Young Physicians in China during the novel coronavirus disease 2019 outbreak. JAMA Netw Open 2020; 3(6): e2010705.
[42] Al Sulais E, Mosli M, AlAmeel T. The psychological impact of COVID-19 pandemic on physicians in Saudi Arabia: A cross-sectional study. Saudi journal of gastroenterology 2020; 26(5): 249-55.
[43] Oh N, Hong N, Ryu DH, Bae SG, Kam S, Kim KY. Exploring nursing intention, stress, and professionalism in response to infectious disease emergencies: The experience of local public hospital nurses during the 2015 MERS outbreak in South Korea. Asian Nurs Res 2017; 11(3): 230-6.
[44] Alsubaie S, Hani Temsah M, Al-Eyadhy AA, et al. Middle east respiratory syndrome coronavirus epidemic impact on healthcare workers’ risk perceptions, work and personal lives. J Infect Dev Ctries 2019; 13(10): 920-6.
[45] Ji D, Ji YJ, Duan XZ, et al. Prevalence of psychological symptoms among Ebola survivors and healthcare workers during the 2014-2015 Ebola outbreak in Sierra Leone: A cross-sectional study. Oncotarget 2017; 8(8): 12784-91.
[46] Jalloh MF, Li W, Bunnell RE, et al. Impact of Ebola experiences and risk perceptions on mental health in Sierra Leone, July 2015. BMJ Glob Health 2018; 3(2): e000471.
[47] Machón RA, Mednick SA, Huttunen MO. Adult major affective disorder after prenatal exposure to an influenza epidemic. Arch Gen Psychiatry 1997; 54(4): 322-8.
[48] Matsuishi K, Kawazoe A, Imai H, et al. Psychological impact of the pandemic (H1N1) 2009 on general hospital workers in Kobe. Psychiatry Clin Neurosci 2012; 66(4): 353-60.
[49] Wu KK, Chan SK, Ma TM. Posttraumatic stress after SARS. Emerg Infect Dis 2005; 11(8): 1297-300.
[50] Kwek SK, Chew WM, Ong KC, et al. Quality of life and psychological status in survivors of severe acute respiratory syndrome at 3 months postdischarge. J Psychosom Res 2006; 60(5): 513-9.
[51] Lee AM, Wong JGWS, McAlonan GM, et al. Stress and psychological distress among SARS survivors 1 year after the outbreak. Can J Psychiatry 2007; 52(4): 233-40.
[52] Maunder R, Lancee W, Balderson K, et al. Long-term psychological and occupational effects of providing hospital healthcare during SARS outbreak. Emerg Infect Dis 2006; 12(12): 1924-32.
[53] Binder LI, Frankfurter A, Rebhun LI. The distribution of tau in the mammalian central nervous system. J Cell Biol 1985; 101(4): 1371-8.
[54] Laurent C, Buée L, Blum D. Tau and neuroinflammation: What impact for Alzheimer’s disease and tauopathies? Biomed J 2018; 41(1): 21-33.
[55] Choi H, Kim HJ, Yang J, et al. Acetylation changes tau interactome to degrade tau in Alzheimer’s disease animal and organoid models. Aging Cell 2020; 19(1): e13081.
[56] Wolfe MS. The role of tau in neurodegenerative diseases and its potential as a therapeutic target. Scientifica 2012; 2012: 1-20.
[57] Babulal GM, Roe CM, Stout SH, et al. Depression is associated with tau and not amyloid positron emission tomography in cognitively normal adults. J Alzheimers Dis 2020; 74(4): 1045-55.
[58] Mohamed AZ, Cumming P, Götz J, Nasrallah F. Department of Defense Alzheimer’s Disease Neuroimaging Initiative. Tauopathy in veterans with long-term posttraumatic stress disorder and traumatic brain injury. Eur J Nucl Med Mol Imaging 2019; 46(5): 1139-51.
[59] Naserkhaki R, Zamanzadeh S, Baharvand H, et al. cis pT231-Tau drives neurodegeneration in bipolar disorder. ACS Chem Neurosci 2019; 10(3): 1214-21.
[60] Cho JH, Johnson GVW. Primed phosphorylation of tau at Thr231 by glycogen synthase kinase 3β (GSK3β) plays a critical role in regulating tau’s ability to bind and stabilize microtubules. J Neurochem 2004; 88(2): 349-58.
[61] Augustinack JC, Schneider A, Mandelkow EM, Hyman BT. Specific tau phosphorylation sites correlate with severity of neuronal cytopathology in Alzheimer’s disease. Acta Neuropathol 2002; 103(1): 26-35.
[62] Demirel ÖF, Cetin I, Turan Ş, Yıldız N, Sağlam T, Duran A. Total Tau and phosphorylated Tau protein serum levels in patients with schizophrenia compared with controls. Psychiatr Q 2017; 88(4): 921-8.
[63] Fernandez LL, Carmona M, Portero-Otin M, et al. Effects of increased iron intake during the neonatal period on the brain of adult AbetaPP/PS1 transgenic mice. J Alzheimers Dis 2010; 19(3): 1069-80.
[64] Brown WR, Thore CR. Review: Cerebral microvascular pathology in ageing and neurodegeneration. Neuropathol Appl Neurobiol 2011; 37(1): 56-74.
[65] Fanni D, Gerosa C, Rais M, et al. The role of neuropathological markers in the interpretation of neuropsychiatric disorders: Focus on fetal and perinatal programming. Neurosci Lett 2018; 669(669): 75-82.
[66] Wirbisky SE, Weber GJ, Lee JW, Cannon JR, Freeman JL. Novel dose-dependent alterations in excitatory GABA during embryonic development associated with lead (Pb) neurotoxicity. Toxicol Lett 2014; 229(1): 1-8.
[67] Romeo B, Choucha W, Fossati P, Rotge JY. Meta-analysis of short- and mid-term efficacy of ketamine in unipolar and bipolar depression. Psychiatry Res 2015; 230(2): 682-8.
[68] Jonas RK, Montojo CA, Bearden CE. The 22q11.2 deletion syndrome as a window into complex neuropsychiatric disorders over the lifespan. Biol Psychiatry 2014; 75(5): 351-60.
[69] Sharon G, Garg N, Debelius J, Knight R, Dorrestein PC, Mazmanian SK. Specialized metabolites from the microbiome in health and disease. Cell Metab 2014; 20(5): 719-30.
[70] Herrmann N, Lanctôt KL, Khan LR. The role of norepinephrine in the behavioral and psychological symptoms of dementia. J Neuropsychiatry Clin Neurosci 2004; 16(3): 261-76.
[71] Matthews KL, Chen CPLH, Esiri MM, Keene J, Minger SL, Francis PT. Noradrenergic changes, aggressive behavior, and cognition in patients with dementia. Biol Psychiatry 2002; 51(5): 407-16.
[72] Crunfli F, Carregari VC, Veras FP, et al. Morphological, cellular, and molecular basis of brain infection in COVID-19 patients. Proc Natl Acad Sci USA 2022; 119(35): e2200960119.
[73] Steardo L, Scuderi C. Astrocytes and the psychiatric Sequelae of COVID-19: What we learned from the pandemic. Neurochem Res 2022; 1-11.