Psychometric properties of the Persian version of the National Stressful Events Survey PTSD Short Scale based on DSM-5 in betrayed women

Abstract

BACKGROUND:

Betrayal trauma, such as marital infidelity, often leads to significant psychological distress, including symptoms consistent with posttraumatic stress disorder (PTSD). Reliable and culturally relevant tools are essential for assessing PTSD in affected populations. This study aimed to evaluate the psychometric properties and confirmatory factor analysis (CFA) of the Persian version of the National Stressful Events Survey PTSD Short Scale (NSESSS-PTSD) in women experiencing marital betrayal.

MATERIALS AND METHODS:

This cross-sectional study assessed the Persian NSESSS-PTSD among 128 women attending psychological clinics in Tehran, Iran. Participants were selected using convenience sampling. The mean age of participants was 35.4 years (SD = 7.8). Research tools included the 9-item NSESSS-PTSD, PTSD Checklist for DSM-5 (PCL-5), Impact of Event Scale-Revised (IES-R), Psychological Well-Being Scale (PWB), and Subjective Happiness Scale (SHS). Data were analyzed using SPSS and AMOS (version 26). Reliability was evaluated through Cronbach’s alpha (internal consistency) and test–retest methods. CFA was conducted to confirm the scale’s structure, and validity was assessed via correlations with related scales.

RESULTS:

The Persian NSESSS-PTSD demonstrated excellent reliability (Cronbach’s alpha = 0.91) and strong test–retest reliability (r = 0.88, P < 0.001). CFA supported a unidimensional structure, with goodness of fit indices (χ²/df = 2.15, CFI = 0.96, RMSEA = 0.05, NFI = 0.91). Convergent validity was supported by significant correlations with PCL-5 (r = 0.81, P < 0.001) and IES-R (r = 0.79, P = 0.001). Divergent validity was demonstrated through moderate negative correlations with PWB (r = −0.51, P = 0.002) and SHS (r = −0.47, P = 0.004).

CONCLUSION:

The Persian NSESSS-PTSD is a reliable and valid tool for assessing PTSD symptoms in betrayed women, providing a valuable resource for clinicians and researchers in culturally similar contexts. The study’s limitations include reliance on convenience sampling, which may affect generalizability, and a cross-sectional design that prevents causal inference. However, its strengths lie in the targeted population, use of DSM-5-based tools, and robust statistical validation procedures, offering novel contributions to PTSD assessment in culturally specific settings.

Introduction

Infidelity has the potential to inflict profound damage on intimate relationships by undermining the essential pillars that support them; specifically, trust, confidence, and security.[1,2] It is widely acknowledged that this refers to any kind of extradyadic activity, whether performed face-to-face or through online channels (including sexual, romantic, or solitary behaviors), that contravenes the exclusivity pacts established by partners.[3]

Infidelity can have a traumatic impact on individuals who have experienced betrayal by their partners, with symptoms consistent with posttraumatic stress disorder (PTSD) frequently observed in this population.[4,5,6] About 60% to 70% of people whose spouses cheat on them experience PTSD, except for criterion A.[7,8,9]

Post-infidelity stress disorder (PISD) is categorized as an anxiety disorder that emerges as a result of significant psychological distress following the revelation of a partner’s infidelity. The term was introduced by Ortman DC in 2005.[10,11,12] Ortman (2005) argued that many individuals who discover their partner’s infidelity interpret this revelation as a profoundly distressing event, often leading to the development of infidelity-related PTSD.[12,13] In a study, 45.2% of the sample reported symptoms suggestive of likely infidelity-related posttraumatic stress disorder.[14] Research indicates that women are nearly twice as prone as men to display symptoms of depression, anxiety, and PISD as a consequence of marital infidelity.[15] For example, according to Ozgun,[16] 34.4% of women who had experienced infidelity outside of marriage fulfilled the criteria for PTSD.

In pertinent studies, a range of instruments has been employed to assess symptoms of post-infidelity stress, including the PCL-5 (PTSD Checklist for DSM-5),[10] The Posttraumatic Growth Inventory (PTGI),[8] Revised Civilian Mississippi Scale of PTSD,[15] and The Life Events Checklist.[17] Research related to Iranian studies on women affected by marital infidelity generally used the following tools for analysis PISD: Impact of Event Scale (IES),[18,19] PTSD Symptom Scale (PSS),[20] Posttraumatic Diagnostic Scale.[21]

National Stressful Events Survey PTSD Short Scale (NSESSS-PTSD) is 9-item self-report scale designed to assess PTSD DSM-5.[22] The original scale comprised 20 items designed to assess all symptoms outlined in the DSM-5 criteria for PTSD. It was validated through a sample of 318 online respondents who met the criteria for probable DSM-5 PTSD. The scale demonstrated excellent internal consistency, with a Cronbach’s alpha of 0.90, and the 20-item version achieved a reliability score of 0.94.[23]

The Iranian version of NSESSS-PTSD was first translated and standardized by Rafie et al.[24] in the earthquake survivor’s community, and Cronbach’s alpha was 0.88. The results of exploratory factor analysis showed that only one factor in the Persian version predicts 51% of the total variance.

The NSESSS-PTSD has been translated into other languages and has been examined. This scale has had good reliability and validity in the South Korean sample (internal consistency; Cronbach’s α = 0.81).[25] In two studies, the Turkish version was obtained in a student sample (Cronbach’s α = 0.87)[26] and a sample of inpatients with alcohol use disorder (Cronbach’s α = 0.88).[27]

PTSD represents a significant mental health challenge, particularly among women who have experienced betrayal trauma.[28] Currently, there are no validated self-report scales for women with betrayal trauma that meet the criteria of the DSM-5 and contain fewer than 10 items. Also, research indicates that the psychometric properties of PTSD scales are crucial for accurate diagnosis and treatment planning, especially in clinical settings.[29]

This study is the first to validate a DSM-5-aligned PTSD scale specifically for betrayed women in Iran. Given the rising prevalence of marital infidelity and its psychological consequences, culturally adapted tools are essential for accurate screening and treatment. The necessity of this research lies in bridging the diagnostic gap for a neglected but clinically significant trauma subgroup.

The purpose of this investigation was to assess the psychometric properties and carry out a confirmatory factor analysis (CFA) of the NSESSS-PTSD in a population of Iranian women affected by marital infidelity.

Materials and Methods

Study design and setting

This study, designed as a cross-sectional analysis, evaluated the reliability and validity of the Persian version of the NSESSS-PTSD specifically in women experiencing marital betrayal. The assessment was conducted using Confirmatory Factor Analysis (CFA) and correlational methods.

Study participants and sampling

The research sample included all female clients who attended specialized psychological clinics located in the third and fourth districts of Tehran. A sample of 128 women, who sought counseling for issues related to their spouse’s infidelity between September and December 2024, was selected through convenience sampling from four clinics.

A sample size of 128 exceeds the minimum requirement for Confirmatory Factor Analysis (CFA), which typically requires a subject-to-item ratio of 10:1.[30] With the 9-item NSESSS-PTSD, at least 90 participants were needed, and a sample size of 100–200 is generally sufficient for validating single-factor models,[31] ensuring the robustness and reliability of the findings.

Research Inclusion Criteria: (1) Aged 18–55 years, with at least one year of cohabitation in a marital relationship. (2) Experienced emotional, physical, or combined forms of marital infidelity. (3) Capable of understanding and independently completing the study questionnaires. (4) Provided written informed consent to participate in the study. Exclusion Criteria: (1) A history of severe psychiatric disorders (e.g., schizophrenia, bipolar disorder, and dissociative identity disorder). (2) A current substance use disorder or severe alcohol abuse. (3) Having experienced other major traumatic events (e.g., physical abuse and natural disasters) within the past six months. 4-Major medical conditions (e.g., neurological disorders and terminal illness) that could impact participation.

Data collection tool and technique

Data were collected at the psychology clinics in Tehran, under controlled conditions to ensure confidentiality and minimize external influences. Initially, participants underwent a screening process to verify their eligibility in accordance with the established inclusion and exclusion criteria. Those deemed eligible were briefed on the objectives of the study, and written informed consent was secured prior to the distribution of the questionnaires. The administration of the questionnaires was overseen by trained researchers, who ensured that all responses were recorded accurately.

National Stressful Events Survey PTSD Short Scale (NSESSS-PTSD): Developed by Kilpatrick et al. in 2013. The NSESSS-PTSD is a nine-item instrument that measures PTSD symptoms aligned with the criteria set forth in the DSM-5. The scale employs a 5-point Likert format, ranging from 1 (not at all) to 5 (extremely), with increased scores indicating a more severe manifestation of PTSD.[25,32] Initial validation reported a Cronbach’s alpha of 0.91, and further studies confirmed this high reliability with a Cronbach’s alpha of 0.92.[23] The Persian version showed a Cronbach’s alpha of 0.90 in a study by Rafiei et al.[24]

PTSD Checklist for DSM-5 (PCL-5): A 20-item scale developed by Weathers et al.[33,34] to assess PTSD symptoms according to DSM-5 criteria. It is rated on a 5-point Likert scale (0 = not at all to 4 = extremely), with higher scores indicating more severe symptoms. Cronbach’s alpha for the original version was 0.94, and an external study by Blevins et al.[35] reported an alpha of 0.95. The Persian version showed a Cronbach’s alpha of 0.91.[36] This scale has also been used in studies of Iranian samples.[37] In the current study, the internal consistency was (α = 0.78)

Impact of Event Scale-Revised (IES-R): Developed by Weiss,[38] this 22-item scale measures distress related to traumatic experiences, including three dimensions: intrusion, avoidance, and hyperarousal. It uses a 5-point Likert scale (0 = not at all to 4 = extremely). Cronbach’s alpha for the original version was 0.96,[39] and a study by Creamer et al.[40] confirmed an alpha of 0.96. The Persian version demonstrated strong consistency, with Cronbach’s alpha coefficients for the three subscales of the IES-R ranging from 0.84 to 0.93.[41,42] In the current study, the internal consistency was (α = 0.89)

The Psychological Well-Being Scale (PWB), developed by Ryff in 1989, assesses well-being through six distinct dimensions. In this study, a condensed version consisting of 18 items was employed, with responses evaluated on a 6-point Likert scale ranging from 1 (strongly disagree) to 6 (strongly agree).[43] Cronbach’s alpha for the original version was 0.94. The Persian adaptation demonstrated strong internal consistency, evidenced (α = 0.82).[44] In this study, good internal consistency (α = 0.90) was obtained.

The Subjective Happiness Scale (SHS), developed by Lyubomirsky and Lepper[45] in 1999, consists of four items designed to assess an individual’s subjective sense of happiness. Respondents evaluate their happiness on a 7-point Likert scale, where 1 indicates minimal happiness and 7 signifies maximal happiness. The initial version of this scale demonstrated a Cronbach’s alpha of 0.86, indicating good internal consistency. In a study of the women, the internal consistency coefficient was found to be 0.83.[46] A Cronbach’s alpha of 0.85 was achieved in this investigation, reflecting a robust internal consistency among the constructs assessed.

Ethical considerations

This research received ethical approval from the Ethics Committee of the Islamic Azad University, Semnan Branch, Iran (Approval Code: IR.IAU.SEMNAN.REC.1403.111).

Statistical analysis method

Data analysis was conducted using SPSS and AMOS (version 26). Descriptive statistics were calculated to summarize demographic data. Confirmatory Factor Analysis (CFA) was performed with the maximum likelihood to validate the scale’s unidimensional structure, with fit indices (χ²/df, CFI, RMSEA, and NFI). Reliability was assessed using Cronbach’s alpha and test–retest reliability via intraclass correlation coefficient (ICC), while convergent and divergent validity were examined using Pearson correlations with related scales.

Results

The sample consisted of 128 women with a mean age of 35.4 years (SD = 7.8), with diverse educational and marital backgrounds. The majority had a Diploma or below (55%), were unemployed (65%), and remained married after infidelity (60%). Emotional infidelity was the most common type (40%), and most participants (80%) had children, often 1–2 (50%). Table 1 shows the results of demographic data.

Table 1.

Comprehensive demographic information of 128 women victims of marital infidelity

Variable		Category		Frequency (%)
Education		Under Diploma and Diploma		(55%) 70
		Bachelor’s		(38%) 49
		Master’s		(6%) 8
		Doctorate		(1%) 1
Employment Status		Employed		(35%) 45
		Unemployed		(65%) 83
Marital Status		Still married		(60%) 77
		Separated		(25%) 32
		Divorced		(15%) 19
Duration of Marriage		1–5 years		(30%) 38
		6–10 years		(40%) 51
		11+years		(30%) 39
Presence of Children		No children		(20%) 26
		1–2 children		(50%) 64
		3+children		(30%) 38
Type of Infidelity Experienced		Emotional		(40%) 51
		Physical		(35%) 45
		Both emotional and physical		(25%) 32
Age		Mean (SD)		35.4 (7.8)

The 9-item Persian version of the National Stressful Events Survey PTSD Short Scale (NSESSS-PTSD) demonstrated excellent results in Confirmatory Factor Analysis (CFA). Each item showed high factor loadings on the latent PTSD construct, ranging from 0.70 to 0.90, indicating strong measurement of the intended construct. The CFA confirmed the scale’s unidimensional structure, with excellent goodness of fit criteria, including χ²/df = 2.15, CFI = 0.96, RMSEA = 0.05, and NFI = 0.91. Table 2 presents the Goodness of Fit Criteria, and Figure 1 shows the Confirmatory factor analysis results.

Table 2.

Goodness of fit criteria for the confirmatory factor analysis (CFA)

Fit index		Value		Acceptable threshold
Chi-square (χ²/df)		2.15		<3
Comparative Fit Index (CFI)		0.96		>0.90
Root Mean Square Error of Approximation (RMSEA)		0.05		<0.08
Normed Fit Index (NFI)		0.91		>0.90

Figure 1.

Confirmatory factor analysis results

Convergent and divergent validity

The findings indicate strong convergent validity, as evidenced by high correlations with recognized PTSD measures such as the PCL-5 (r = 0.81, P < 0.001) and IES-R (r = 0.79, P < 0.001). Conversely, divergent validity was shown through moderate negative correlations with constructs like psychological well-being (r = −0.51, P < 0.01) and happiness (r = −0.47, P < 0.01). This further substantiates that the scale is focused on PTSD-specific symptoms while remaining distinct from unrelated psychological constructs. The convergence and divergence results are reported in Table 3.

Table 3.

Descriptive statistics and correlation matrix for NSESSS-PTSD and related scales

Variable		Mean		Std. Dev.		NSESSS-PTSD		PCL-5		IES-R		PWB		Happiness
NSESSS-PTSD		18.2		4.3		1.00
PCL-5		45.7		8.5		0.81		1.00
IES-R		36.8		7.9		0.79		0.76		1.00
PWB		52.4		6.4		−0.51		−0.48		−0.49		1.00
Happiness Scale (SHS)		56.7		5.8		−0.47		−0.44		−0.46		0.55		1.00

Reliability

The test–retest reliability of the Persian NSESSS-PTSD over a two-week interval was excellent (ρ = 0.88, P < 0.001), indicating the stability of the instrument over time. The internal consistency of the Persian NSESSS-PTSD was high, with a Cronbach’s alpha of 0.91, indicating excellent reliability for measuring PTSD symptoms.

Discussion

The aim of this study was to evaluate the psychometric properties of the NSESSS-PTSD in women affected by marital infidelity. The results of this research provide robust evidence supporting the validity and reliability of the Persian version of the NSESSS-PTSD.

The unidimensional structure of the Persian NSESSS-PTSD, confirmed through Confirmatory Factor Analysis (CFA), was also consistent with previous studies, such as those conducted in South Korea and Turkey. Kim et al.[25] confirmed the unidimensional structure of the scale among Korean psychiatric outpatients, while Evren et al.[26] and Evren et al.[27] similarly established the scale’s unidimensionality in Turkish inpatient and undergraduate student samples, respectively.

In terms of reliability, the scale demonstrated excellent internal consistency, indicating that the items are strongly correlated and together provide an effective measurement of PTSD symptoms. The excellent Cronbach’s alpha in this study indicates strong internal reliability, which is essential for the accurate measurement of PTSD. Cronbach’s alpha values above 0.80 are generally considered to indicate good reliability.[47] This finding aligns with prior studies that have reported high internal consistency for the NSESSS-PTSD across various samples. For example, in the study by Kim, et al.,[25] Cronbach’s α for the scale was reported as (α = 0.81), demonstrating good internal consistency in their sample of Korean psychiatric outpatients. Similarly, in a study with Turkish inpatients with alcohol use disorder, Evren et al.[26] reported a Cronbach’s alpha of 0.88, while in the Turkish undergraduate student sample, Cronbach’s α was also high (α = 0.87).[27] Additionally, in the Persian translation of the NSESSS-PTSD for Iranian, Cronbach’s alpha was found to be very high (α = 0.88), consistent with the original English version (α = 0.91).[24]

These results directly support the original aim of validating the psychometric performance of NSESSS-PTSD in betrayed women. The high factor loadings and strong correlations with PCL-5 and IES-R underscore its clinical relevance. Furthermore, the negative associations with well-being and happiness scales validate its discriminant capability. These findings align with the hypothesis that the scale reflects PTSD-specific symptoms.

The evidence for convergent validity was robust, as indicated by significant correlations with recognized PTSD assessment tools such as the PCL-5 and IES-R. This observation aligns with findings from earlier research that demonstrated strong associations between the NSESSS-PTSD and various other PTSD measurement instruments. For instance, in their study, Kim et al.[25] reported a Pearson correlation of r = 0.78 between the NSESSS-PTSD and the PCL-5, indicating high convergent validity. Similarly, Evren et al.[27] observed a Pearson correlation of r = 0.77 with the PCL-C in their study of the Turkish version of the scale with alcohol use disorder patients. The strong convergent validity observed in this study suggests that the Persian version of the NSESSS-PTSD effectively measures PTSD symptoms in a way similar to well-established instruments.

Divergent validity was also demonstrated in this study, as evidenced by moderate negative correlations with measures of psychological well-being and happiness. This supports the claim that the NSESSS-PTSD is measuring PTSD-specific symptoms rather than other psychological constructs, aligning with the findings of Kim et al. (2022), who demonstrated similar patterns of divergent validity in their evaluation of the scale among Korean psychiatric outpatients. Moreover, the negative correlations with psychological well-being and happiness observed here are in line with previous research conducted on Iranian earthquake survivors,[24] further confirming the scale’s ability to distinguish PTSD from other unrelated constructs.

Limitation and recommendation

This study’s findings are limited in their applicability to broader populations as a result of utilizing convenience sampling from a single geographic area. Moreover, the cross-sectional design employed in the research precludes the possibility of determining causal relationships between betrayal trauma and PTSD symptoms.

Subsequent studies might benefit from a larger sample size that reflects various cultural backgrounds and the implementation of longitudinal designs to examine the prolonged effects of betrayal trauma. Furthermore, an investigation into the gender differences in PTSD symptoms related to betrayal trauma may offer important perspectives.

Conclusions

The NSESSS-PTSD demonstrates excellent psychometric properties, including strong reliability, validity, and a unidimensional structure. These results make it a reliable tool for assessing PTSD symptoms in betrayed women and contribute to the growing body of research supporting the use of the NSESSS-PTSD across diverse populations and cultural contexts.

AI policy disclosure:

No AI used in writing or data analysis.

Conflict of interest

The authors have reported no conflicts of interest.

Funding Statement

This study was not supported by any specific funding from public, commercial, or non-profit organizations.