A COVID Stress Syndrome, which is mainly characterized as being anxious and frightened to be contaminated, has been introduced. Despite the fact that contamination fear is a type of OCD symptom, there is minor focus on patients with obsessive-compulsive disorder (OCD), the life prevalence of which is approximately 2% of the population. Patients’ vulnerability may be strengthened during COVID-19; exacerbation of OCD symptoms, especially contamination fear, has been reported following previous epidemic disease outbreaks such as SARS-CoV, partly since both diseases arouse a fear of infection, which is a trigger of contamination fear, and requires a thorough hand-washing.
The Coronavirus Disease 2019 (COVID-19) exerts variable impact on patients with obsessive compulsive disorders (OCD). There remains a challenge to determine the extent to which OCD is exacerbated due to the pandemic. Therefore, our aim is to explicate the latest researching progress of OCD under COVID-19 based on a review of 15 existing articles. Our review confirms the prevalence of OCD exacerbation in different age groups and particular symptoms. However, it also reveals nonconformity among research, lack of investigation in OCD treatment, and imbalance in OCD symptoms research. Further, we discuss the probable reasons of the exacerbation and current situation of OCD treatments. Finally, based on our discussion, we offer suggestions on how to manage OCD under the new circumstance, including the introduction of new policies, the use of communications technology, the improvement of researching methods, and possible angles for further research.
2. Obsessive Compulsive Disorders
The Coronavirus Disease 2019 (COVID-19) is a contagious respiratory disease which has greatly affected the world, and was defined as a pandemic on 11 March 2020 . The world has recently reached an unpalatable milestone of 100 million patients and 2 million related deaths . This fast-spread disease undoubtedly causes worldwide anxiety. Besides the potential probability of being infected, the general adaption of quarantine measures, the worrisome slowdown of economies, and the curtailment of forms of social interaction are all factors contributing to greater mental health concern during the pandemic. Studies investigating public mental health during COVID-19 are constantly progressing. A COVID Stress Syndrome, which is mainly characterized as being anxious and frightened to be contaminated, has been introduced . Despite the fact that contamination fear is a type of OCD symptom, there is minor focus on patients with obsessive-compulsive disorder (OCD), the life prevalence of which is approximately 2% of the population. Patients’ vulnerability may be strengthened during COVID-19; exacerbation of OCD symptoms, especially contamination fear, has been reported following previous epidemic disease outbreaks such as SARS-CoV , partly since both diseases arouse a fear of infection, which is a trigger of contamination fear , and requires a thorough hand-washing . Though effective studies have been done, the nonnegligible impact of COVID-19 on OCD is still not adequately investigated. OCD symptomatology and treatment trajectory post-pandemic need further research. In this context, we intend to explicate current explorative findings about variations in OCD under COVID-19, mainly focusing on symptoms, treatments, and related factors, based on existing literature.
3.1. OCD Symptoms
Articles illustrate the exacerbation of OCD from different aspects. They discuss scores, symptom occurrence, remission rate, prevalence rate, and different age groups. The heterogeneous OCD symptoms can be summarized as eight classes 
. The core symptoms of OCD are obsessions and compulsions 
. Among those various symptoms, fear of contamination is the most prevalent 
, which is reported as increasing in severity by articles included and not included in this review 
. Since washing hands thoroughly is recommended in order to prevent infection, this OCD symptom is the most frequently investigated 
. Two in thirteen articles of research solely focus on contamination fear 
, and three refer to this symptom, all indicating that this symptom worsens under COVID-19. Some other research shows no difference before and under COVID-19 in contamination fear in certain regions, or if patients’ syndromes were formed before the pandemic 
. Hoarding, which is characterized as a separated group of OCRD, is reported as aggravated. There are conflicts between Cox et al. 
and Khosravani et al. 
in several aspects. Cox et al. 
suggest that there is not prevalent exacerbation in various OCD symptoms, since some of them, including checking, remain the same under COVID-19. Chakraborty et al. 
and Storch et al. 
hold the same opinion from another angle. The former finds that 51.2% of patients have symptom exacerbation, and the latter illustrates that 47% stay the same, which indicates that exacerbation is not prevalent. However, Khosravani et al. 
illustrate that there is an extensive increase in various symptoms, and checking exacerbates under COVID-19. Therefore, there are conflicts between studies, but exacerbation under the epidemic exists. Despite the differences between the two studies, symptoms of depression that developed before the pandemic significantly and uniquely predicted a small increase in hoarding after the outbreak 
. As for other specific symptoms, harm, unacceptable thoughts, and symmetry are reported to be exacerbated under COVID-19 
Four articles included in this review use the Y-BOCS score to estimate the severity of OCD and all find out that there is a rise in the Y-BOCS score 
. OCD prevalence rate is higher than it was before COVID-19 
. Some researchers found out that the number of relapsing patients with OCD grows 
. As for different age groups, three articles mainly focus on children and adolescents 
. It is probable that additional symptoms may develop, or original symptoms may worsen among young subjects 
, and they also have a high rate of remission, so their clinicians should adjust therapies accordingly. Moreover, despite the fact that remission is reported in other studies, there is no comparison of the remission rate among different age groups. The comparison would provide a good chance to estimate the ability of different age groups coping with OCD.
The reason why OCD worsens under COVID-19 is also discussed by articles. As for exterior factors, COVID-19 is considered as a source of anxiety which spreads via emotional contagion. Consumption of media spreads anxiety 
, and inter-reaction between psychological disorders complicates under the pandemic. People mainly use social media to obtain the latest news of the pandemic. Results reveal that people spend hours viewing news of COVID-19 
. Perhaps, the constant exposure to social media which send news reports and health tips emphasizing the importance of self-sanitation, which may result in greater concern of being infected, becomes stimuli of OCD symptoms. For those whose symptoms are caused by interpersonal actions, their symptoms may alleviate temporarily. As for interior factors, it is also revealed that patients with insomnia are more likely to suffer from OCD under COVID-19 
. Other articles suggest that symptoms that refer to danger and contamination and remission status are important reasons for OCD exacerbation 
. Thus, various factors should be included and adjustments should be made according to the patients’ personal situations.
3.2. OCD Treatments
The differences between OCD treatments before and during the pandemic can be concluded to four aspects: (1) there is a prevalent rise in anxiety in the social, economic, and political environment. (2) It is likely that hospitals and other treatment centers will be shut down for several months, reducing the efficiency of the communication between clinicians and patients. (3) Patients’ living environments are changed, as well as their social interaction ways and interpersonal relations. (4) A temporary absence from work can have an effect on patients’ mental situations. Pharmacological and psychological interventions for the management of OCD are wielded. Under COVID-19, as a result of impact on global economy and the adaptation of quarantine measures, variation in both methods occur. Articles on this aspect are relatively low in quantity. Among the selected articles, only one focuses on treatment methods.
ERP and CBT are the most prevalent ways to treat OCD, and are considered a gold treatment 
. However, ERP courses’ effects on OCD treatments under COVID-19 are limited, and the mechanism behind them remains unclear 
. As a key exterior factor, it is particularly worrying that patients’ living environments is transforming under COVID-19, causing an impediment to their treatments. For instance, support from family or individuals are indispensable for OCD therapies. Family members and caregivers of OCD patients are also at a greater risk of developing stress-related illnesses and may need additional support due to the worsening of the patient’s symptoms 
. It can be concluded that OCD patients’ participation in therapies is affected, since anxiety is growing in their living environment. We assume that an increase in depression severity interferes with ERP, for it is suggested that aggravation of fear and depression may cause obstruction in OCD treatments 
Pharmacological treatments rely on medicine supply. The selective serotonin reuptake inhibitors (SSRIs) are the main choices of pharmacological treatment. Though solely listed as a control variable, there have already been reports that patients have stopped taking their medicines due to unavailability at the nearby drug stores 
. Regulatory restrictions and virus-related manufacturing problems are disrupting global drug supply chains. Despite the fact that there are challenges to the reserve medical supplies in China 
, no reports claimed a rise in domestic SSRIs prices. However, the inevitable economic recession under COVID-19 may add a financial burden to certain patients or curtail medical supply channels, and domestic SSRIs may be more used than foreign ones. Moreover, it is concerning whether patients tend to increase their amount of medicine under COVID-19.
3.3. Implications for OCD Investigation, Therapies and Health Policy
It is undoubted that the epidemic offers a valuable chance to study OCD symptoms and recession. We assume that a complex interaction mechanism may lead to deterioration in some of these symptoms, while, as one’s living environment is considered safer or relatively different, the other symptoms may be remitted temporarily. For instance, the NIMH Global Obsessive Compulsive Scale (NIMH-GOCS) score increased in people with financial stress or unemployment, reflecting a deterioration in the severity of OCD. In contrast, patients without a financial burden showed relatively stable NIMH-GOCS 
. It is also not hard to imagine that, for instance, a person with the fear of harming others may convert to contamination fear. More research is needed to understand more interactions between social factors that lead to the exacerbation of OCD symptoms. There is incongruity between studies, probably as a result of regional differences, of the unclear definitions of prior symptoms and of those that were newly formed during the pandemic, or of the limitation of sample capacity.
Both interior and exterior factors hinder OCD therapies. There are a number of concerns referred to this position 
. We assume that the main obstacle for treatment effectiveness is the inefficiency of psychotherapy, since patients and their clinicians’ interaction is limited. As is illustrated, the improvement of the effectiveness of OCD treatment may need the cooperation between clinicians and patients 
. Clinicians ought to have a proper attitude towards the pandemic and infection. They may search for effective ways and take advantage of current forms, for instance, telemedicine and smartphone interventions 
, to make effective communication with their patients, and adjust therapies simultaneously, taking advantage of remote assistance 
. Nonetheless, face-to-face meetings are always recommended for their better therapeutic effects. They may also discuss their treatment procedures with patients explicitly. While these proposed adjustments attempt to take note of the current pandemic and CDC guidelines, it is important to note that deviations from established patterns can have potentially negative consequences, even if they are temporary. There is also a need to enhance the prevention of relapse during social restrictions as well as to develop other strategies 
, since there is research indicating that the relapsing rate rose during the pandemic 
. Clinicians should not only treat patients that are still suffering from OCD, but also focus on the prevention of relapsing OCD 
. Moreover, since psychiatric medicine is generally put on a longer-term administration and has relatively more doses than depression 
, to guarantee supplies for such medicines is indispensable under the pandemic, especially when hospitals or pharmacies are closed during the quarantine. Patients should be at least informed about their access to their drugs. Policies should be introduced to prevent shortages and price rising in peculiar medicine.