Introduction
Obsessive-compulsive disorder (OCD) is characterized by unwanted thoughts, images or tendencies (obsessions), which are followed by repetitive behaviors or mental acts (compulsions) experienced in response to anxiety or other unfavorable emotions [1]. Obsessive-compulsive symptoms (OCSs) usually occur in a non-clinical, subclinical, and clinical continuum that differ in the severity of cognition and symptoms, but they are qualitatively identical in nature. Thus, most of the subclinical OCSs may progress to OCD, if left untreated [2]. Epidemiological studies in the United States report that about 28.2% of people in the community have experienced OCSs at least once in their lifetime [4]. Furthermore, according to an epidemiological study in Iran, the prevalence of OCS among adolescents was found as 11.2% [5]. Defective emotional schemas are associated with OCSs [5]. The emotional schema model states that individuals have different perspectives about emotion and emotion regulation, which cause problematic strategies to cope with emotions, such as suppression, rumination, avoidance, blaming, and substance abuse [10]. Emotion regulation is defined by Gross as: “the processes, by which individuals influence which emotions they have, when they have them, and how they experience and express these emotions” [12]. Moreover, it seems that defective emotion regulation may be associated with a growth in repetitive efforts to avoid emotional experiences [13]. Thus, experiential avoidance (EA) may play a key role in the formation and persistence of a number of mental health-related disorders, like anxiety, depression, and OCD [14]. In addition, interest in understanding the cognitive processes involved in the pathology of OCD has increased in recent years. One of the cognitive factors that has attracted little attention is rumination. It is believed that rumination may aggravate the OCSs [17]. 
To the best of the author’s knowledge, a study examining the mediating role of emotion dysregulation, rumination, and experiential avoidance in the relationship between OCSs and emotional schemas has not yet been done. Thus, this study was designed to examine a more comprehensive model of OCSs.

Methods
This is a descriptive-correlational study, which was done using the structural equation modeling method (SEM). The Sobel test was used to evaluate the mediating role of emotion dysregulation, experiential avoidance, and rumination. The sample included 349 students selected by convenience sampling from the universities of Tehran. The inclusion criteria were being a college student and the age of 20-40 years. Further, participants were excluded if they had psychosis, bipolar disorders, post-traumatic stress disorder (assessed by self-declaration) as well as substance use disorder (assessed by questionnaire). Due to the COVID-19 outbreak, the data collection process was done online. The Obsessive Compulsive Inventory-Revised (OCI-R), Leahy’s Emotional Schemas Questionnaire (LESS), Difficulty in Emotion Regulation Scale (DERS), The Ruminative Response Scale, Acceptance, and Action Questionnaire-II (AAQ-II), and Drug Use Disorders Identification Test (DUDIT) were used to collect the data.

Results
According to the fit values, the proposed model had a good fit (Table 1). Moreover, the Sobel test was used to investigate the mediating role of emotional dysregulation, rumination, and experiential avoidance in the relationship between emotional schemas and OCSs. Considering that at the error level of 0.05 (α=0.05) and the significance level of less than 0.05 for all of these three variables, it can be said that their mediating role was statistically significant.




Discussion
The results show that the relationship between emotional schemas and OCSs via emotion dysregulation was statistically significant. Consistent with this result, Stern et al. found that the anxiety associated with OCSs is significantly associated with low emotional awareness and fear of positive and negative emotions [38]. In addition, in explaining the present findings, we can also refer to Leahy’s emotional schema model. This model states that negative beliefs about emotions lead to the use of ineffective strategies to deal with them. As a result, if a person has some negative beliefs about their emotions, they will use dysfunctional emotion regulation strategies, such as avoidance and repression, which in this case, obsessions can be considered a way to suppress and avoid the experiencing of emotions [8]. Furthermore, findings showed that rumination is a significant mediator of the relationship between emotional schemas and OCSs. Individuals who do not believe that their emotions are considered valid by others and that their emotions are not understandable to them have low acceptance of their emotions and are more likely to ruminate [8] and this rumination can be the basis of obsessive thoughts and behaviors. 
About the mediating role of experiential avoidance (, we can refer to the findings of Rezaei et al. [20], Angelakis et al. [4], and Briggs et al. [45].
Leahy et al. [46] also showed that maladaptive emotional schemas have a positive and significant correlation with experiential avoidance and can significantly predict it. Leahy believes that adaptive emotional schemas lead to a moment-by-moment increase in mindfulness (reduced experiential avoidance), acceptance, and experience of emotions [44]. In addition, it can be stated that experiential avoidance plays a key role in the formation and continuation of OCD. Considering that the prevalence of intrusive thoughts in people with OCD is not more than in the general population, probably the meaning that the first group gives to these thoughts and then avoids their experience is the basis for the formation of symptoms. The present study highlights the important role of emotion dysregulation, experiential avoidance, rumination, and emotional schemas in the formation of OCSs. However, the interpretation of findings must be considered along with the study’s limitations. For example, due to the prevalence of COVID-19 and the closure of universities, it was not possible to conduct the data collection process in person and select participants randomly. Therefore, the convenience sampling method was inevitably used and the data were collected online. Furthermore, the sample was non-clinical; thus, it can make it complicated to generalize the findings of this study to clinical and subclinical groups. Future studies would benefit from incorporating participants with a diagnosis of OCD based on a structured clinical interview for DSM-5.

Ethical Considerations

Compliance with ethical guidelines
The present study was approved by the ethics committee of Iran University of Medical Sciences (Code: IR.IUMS.REC.1400.294).

Funding
This study was extracted from the MSc thesis of Fatemeh Nazari, approved by Iran University of Medical Sciences. The authors received no financial support for research..

Authors contributions
Conceptualization, project administration, research, writing original draft, review, validation: Fatemeh Nazari; Conceptualization, validation, supervision, writing, review and editing: Banafshe Gharaee; Methodology, formal analysis and editing: Komeil Zahedi Tajrishi.

Conflicts of interest
The authors declared no conflict of interest.