1. Introduction
ultiple sclerosis (MS) is a debilitating, chronic, and progressive disease of the myelin of the central nervous system, which moderately to severely affects the physical, sensory, cognitive functions of the brain and spinal cord [1, 2]. Clinical symptoms of this disease include decreased function in the limbs, muscle spasms, loss of intestinal or bladder control, impaired sexual function, unstable fatigue, reduced vision, ataxia, pain, cognitive function loss, and emotional changes [3]. The cause of MS is still unknown. It is a complex disease with multiple genetic and environmental factors [4]. Most people with MS experience relapses [3]. This disease, like all chronic diseases, has a dialectical nature that is expressed as the paradox of chronic diseases. In other words, confronting the constraints of life to realize more possibilities and accepting the constraints to avoid conflict with the immutable restrictions [5]. As a result, the disease itself is a stressful situation [6], and stress plays a role in activating the disease and making it worse [3]. Studies have shown that 63% of patients with MS experience moderate to severe stress [7], and the strongest and most important factor in the adaptation of MS patients is perceived stress [6]. Stress can even destroy the myelin of the brain in patients with MS [8]. Meta-analytic studies have also shown that, although stress plays a role in the onset, recurrence, and exacerbation of MS symptoms, the role of perceived stress has been less considered [9]. Although a consistent association has been found between stress and disease exacerbation, and stress exacerbates neurological symptoms of the disease, it reduces the quality of life, factors such as personality traits, life experiences, and cognitive teachings influence people’s assessment of stress. Thus, responding to stress is a personal and dynamic process [3, 4, 5, 6, 7, 8, 9, 10], and it depends on the person’s internal resources to deal with stress.
Internal resources are described as the innate aspects of a person used to deal with stressors, such as chronic diseases. These resources include spiritual intelligence, a sense of cohesion, cognitive flexibility, hope, etc. [10]. When people find out that they have a chronic and life-threatening disease, they ask existential and spiritual questions. Spirituality, as an internal resource, creates power in people that helps them to adapt to life events such as diseases, especially in situations where there is severe stress and is out of the individual’s control [11]. Spirituality brings the person a sense of connection with others and excellence, and a sense of inner peace and wellbeing through faith and searching for meaning and purpose in life. A robust spiritual connection improves life satisfaction and makes a person adapt to disability [12]. One of the dimensions of spirituality is spiritual intelligence; spiritual intelligence is a higher level of intelligence that activates the qualities and abilities that give a person credibility in wisdom, compassion, honesty, integrity, joy, love, creativity, and peace. Spiritual intelligence is a more profound sense of meaning and purpose [13]. It includes the capacity for flexibility, a high degree of self-awareness, the capacity to face suffering, the ability to face and transcend pain, the quality of being inspired by values, ignoring the source of unnecessary harm, having a tendency to see the connection between different things, searching and asking the fundamental questions of life [14]. Besides spirituality, to cope with the limitations and sources of stress and stay healthy, a sense of coherence is needed [15]. According to Antonovsky’s theory, a sense of coherence is an internal resource that grows empirically during adolescence to reach a relatively stable level. A sense of coherence can explain why a person can overcome high levels of stress and stay healthy. A developed and robust sense of coherence promotes physical health and facilitates high levels of psychological wellbeing. It is a general, stable, and all-encompassing orientation that 1. Makes stressors predictable, orderly, and understandable; 2. Helps the person have sufficient resources to manage stressors; and 3. Makes the person feel that life is meaningful. Because life has problems and challenges that must be overcome, not just be endured. Sense of coherence is negatively related to stress and has a positive effect on the quality of life. Patients with a low sense of coherence are less able to cope with their problems without the help of others [13]. Sense of coherence does not refer to a specific coping strategy but rather to factors that underlie successful coping with stressors in all cultures [16]. Another internal resource for dealing with stress is cognitive flexibility, which can change cognitive preferences to adjust to changing environmental stimuli and new situations [16].
The critical thing about MS is that it has been growing over the last two decades, especially among young people. The prevalence of this disease in Kerman City, Iran, is about 60 per 100000 population and is three times higher in women than in men [17]. Undoubtedly, environmental factors such as stressors are effective; stress and psychological factors play an important role in exacerbating MS. For MS patients, what is recommended more than medications and treatments is to avoid anxiety, stress, and tension [18]. This study investigates the effects of internal resources (spirituality, sense of coherence, cognitive flexibility) in predicting perceived stress in patients with MS. Identifying stress predictors can be useful in stress management and reducing MS symptoms.
2. Materials and Methods
This research is a descriptive correlational study conducted on 156 patients with MS who were selected using a convenience sampling method. Data collection tools were as follows. 
Perceived Stress Scale (PSS)
The Perceived Stress Scale (PSS) is the most widely used psychological tool to measure the perception of stress and the degree to which situations in one’s life are appraised as stressful [19]. Data are rated on a scale from “never” to “very often”. The total score ranges from 0 to 56. Cohen et al. reported a test-retest reliability of 0.85 and an internal consistency of 0.84 for this tool. For the Iranian population, the Cronbach alpha coefficients of perceived self-efficacy, perceived distress, and PSS were reported as 0.80, 0.60, and 0.76, respectively [20]. In our study, it was obtained as 0.75.
Spiritual Intelligence Self-report Inventory (SISRI) 
Spiritual intelligence self-report inventory was developed by King [21] and has 24 items and the subscales of critical existential thinking, personal meaning production, transcendental awareness, and conscious state expansion. A higher score in this questionnaire indicates higher spiritual intelligence. The reliability of the Persian version of SISRI was estimated to be 0.88 [22]. Psychologists confirmed the face and content validity of Persian SISRI. To assess its convergence validity, the correlation coefficient between SISRI and the spiritual experience questionnaire of Ghobari Bonab was examined and reported as 0.66. Exploratory factor analysis and first-order confirmatory factor analysis were used to calculate its construct validity. The results showed that the Persian version of SISRI is a reliable tool for measuring spiritual intelligence. Because of its acceptable validity and reliability, it can be used in educational and research environments. In this study, its reliability was obtained as 0.93.
Sense of Coherence Scale (SOC) 
Sense of Coherence Scale (SOC) assesses how people use their resources to overcome stress and was designed by Antonovsky [15]. It has 29 items rated on a scale from 0 to 7. Its score ranges from 29 to 203. The Cronbach alpha for internal consistency of SOC ranges from 0.82 to 0.95 [16]. In this study, the reliability of the Persian SOC was obtained as 0.76.
Cognitive Flexibility Inventory (CFI)
Cognitive Flexibility Inventory (CFI) is a self-report scale with 20 items developed by Denis and Vander Wal [17]. They reported a concurrent validity of -0.39 using the Beck depression inventory and a convergence validity of 0.75 using Martin and Robin’s cognitive flexibility scale. It has two alternatives and control subscales measuring three aspects of cognitive flexibility: the ability to generate multiple alternative solutions to difficult situations, the ability to perceive numerous alternative explanations for life events, and the tendency to perceive difficult situations as controllable. Share et al. [23] reported a total scale test-retest reliability of 0.71 and a Cronbach alpha coefficient of 0.90 for overall Persian CFI. In this study, the reliability coefficient of 0.84 was obtained.The collected data were analyzed in SPSS v. 24.
3. Results
Of 156 participants, 80.8% (n= 126) were females and 19.2% (n=30) males ranging in age from 19 to 68 years mean±SD age = 35.27±18.9 years. Also, 50% were married, but 35.3% were single, and 3.8% were divorced. About 2.6% had undergraduate education, 46.2% a high school diploma, and 46.2% a bachelor’s degree. Regarding income status, 28.8% of them had poor economic status, 62.2% moderate status, and 7.1% high status. The duration of the disease in 33.3% of them was 0-5 years, in 42.9% 5-10 years, and in 19.2% 10-15 years. Also, 23.7% were first child, 33.3% second child, 17.9% third child, 9% fourth child, and 16.1% had a birth order >4 (Table 1). 


The Pearson correlation test was used to determine the relationship between research variables whose results showed a significant relationship between them. Stepwise multiple regression analysis was used to investigate the role of spiritual intelligence components, sense of coherence, and cognitive flexibility in predicting perceived stress. For the assumption of independent errors, the Durbin-Watson test was used. If the test result were in a range of 1.5-2.5, there would be no correlation between the errors. Another assumption is collinearity or a correlation between independent variables. In this regard, the collinearity was tested with two statistics of tolerance and Variance Inflation Factor (VIF). So, tolerance less than 0.01 and VIF greater than 10 indicates the presence of collinearity. According to the results, both assumptions were met. Table 2 presents the coefficient of multiple correlations and the coefficient of determination for spiritual intelligence, sense of coherence, and cognitive flexibility. 


As can be seen, meaningfulness (SOC), perception of controls (CFI), Transcendental Awareness (SISRI), and perception of alternatives (CFI) explain 37% of the variance in perceived stress, where meaningful life with 23% effect had the most significant role in explaining the perceived stress of patients with MS. Table 3 presents the output of the stepwise regression model. 


Regression coefficients with standardized beta weights show that a simultaneous change in meaningfulness, perception of controls, transcendental awareness, and perception of alternatives causes 0.28, 0.30, 0.33, 0.18 change in perceived stress, respectively. Comparing the beta coefficients of these variables with each other shows that meaningful life with a standard coefficient of -0.488 had the most negative effect on perceived stress.
4. Discussion
When people face a chronic and life-threatening disease such as MS, their lifestyle changes create stress that contributes to the disease’s persistence. It is imperative to reduce the stress caused by these conditions. This study aimed to predict the perceived stress of MS patients based on the internal resources of coping with stress. The results showed that among the components of spiritual intelligence, “transcendental awareness” predicted perceived stress in MS patients. Transcendental awareness means going beyond the physical and material state of oneself. In other words, it refers to the capacity to understand the all-encompassing dimensions of oneself (self-transcendent), others, and the physical world (non-materiality). This issue means that in the normal state of awareness, the spiritual dimensions of oneself and others and life should be considered. Le and Lavenson defined the self-transcendent as “the ability to move beyond self-centered consciousness, and to see things with a considerable measure of freedom from biological and social conditioning”. It means that people can know themselves beyond biological and physical forms. Continuous knowledge and awareness of oneself is a key component of this ability. King and DeCicco [22] also state that transcendental awareness evokes a sense of security in the individual and acts as a source of coping with a crisis. Other studies have shown the adaptive role of spirituality in people with various diseases, including cancer, spinal cord injury, and substance abuse [22]. They have stated that spirituality as a supportive resource helps reduce stress [12]. Religious beliefs and spirituality have a positive relationship with coping with stress such that when spirituality is expressed through religious beliefs, a person is more resistant to stress [25]. These studies have not shown which dimension of spiritual intelligence has a more influential role in predicting stress and coping with problems.
Among the components of a sense of coherence, “meaningfulness” could predict perceived stress in MS patients. A sense of coherence is a kind of attitude and a stable orientation towards life, a person’s perspective, and capacity to respond to stressful situations [26]. Meaningfulness means that life problems are worth investing our time and energy to solve them [27]. This component leads people to understand the personal world and the resources that are at their disposal. Antonovsky argued that people with this trait are very hardworking and resilient to stress [28]. Johnson also reported a relationship between stress and a sense of coherence that has a stronger relationship with mental health (e.g. stress) than physical health (e.g. pain) [29]. This finding is consistent with the finding that the sense of coherence is related to stress and mental health and is one of the essential resources that can prepare people to deal with problems.
Two cognitive flexibility components, including “controls” and “alternatives”, could predict perceived stress in MS patients. Cognitive flexibility means the ability to modify behavior in response to environmental changes. Deficiency in this skill contributes to the emergence and persistence of stress-related diseases [30]. Cognitive flexibility gives a sense of mastery over difficult situations by selecting alternatives to human life events and behavior, and can therefore be related to perceived stress levels. This finding is consistent with other studies that stated that people with cognitive flexibility could use alternative justifications when facing stress and positively change their mindset and use it to cope with stress [31]. Shields et al. [32] also reported the relationship between stress and cognitive flexibility.
When people face difficult situations, the first questions are: “What problems do I have to deal with? What resources do I have?” “How can I create meaning for these problems?” and “What strategies should I use to cope with these problems?” Difficult conditions stimulate a person’s spiritual sense to look beyond the physical form called “transcendental awareness”. Another step is the sense of meaning, where one creates meaning for these challenging conditions, which is the motivational aspect of “sense of coherence”. The final ability is cognitive flexibility that helps people look for alternative solutions in problematic situations to deal with constraints and feel that they can control and overcome problems. Although stress management programs have increased the quality of life in patients with MS, they have not significantly reduced their perceived stress [33]. Stress management programs typically focus on cognitive components, such as challenging negative thoughts, redefining life goals; behavioral and physical elements like breathing control and relaxation, acceptance-based and mindfulness-based components; positive emotions, including happiness, hope, and compassion [34]; skills training such as coping skills training and assertive behavior [35]; and external environment such as receiving social support [9]. However, the role of internal resources in coping with stress has not been fully considered. In Figure 1, we recommend integrating internal resources of coping with stress in routine stress management programs.  This model can be used in stress management programs for greater effectiveness.
5. Conclusion
Meaningfulness, transcendental awareness, and perception of alternatives and controls predict perceived stress in MS patients. In stress management programs, emphasis should be placed on these factors so that the stress management program becomes more effective.

Ethical Considerations
Compliance with ethical guidelines
All ethical principles are considered in this article. The participants were informed of the purpose of the research and its implementation stages. They were also assured about the confidentiality of their information and were free to leave the study whenever they wished, and if desired, the research results would be available to them. This study was approved by the Ethics Committee of the University of Kerman University of Medical Sciences (IR.KMU.REC.1398.347).

Funding
This study received financial support from the Neurological Diseases Research Center of Kerman University of Medical Sciences.

Authors' contributions
All authors contributed in preparing this article.

Conflicts of interest
The authors declared no conflict of interest.


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