Introduction

Dissociative identity disorder (DID) remains a complex and enigmatic condition characterized by the presence of two or more distinct personality states or identities within an individual, accompanied by memory gaps and recurrent episodes of amnesia (American Psychiatric Association, 2013). While DID has garnered considerable attention in clinical and research domains, its assessment and measurement present ongoing challenges due to the heterogeneous nature of dissociative experiences and the subtle yet significant variations in symptomatology across individuals (Brand et al., 2009).
Existing measures of dissociation often lack specificity and fail to capture the nuanced manifestations of dissociative phenomena, particularly in the context of comorbid psychiatric conditions or subtle dissociative symptoms that may not meet the diagnostic threshold for DID (Steinberg et al., 2013). Moreover, the assessment of pathological traits associated with dissociative experiences, such as identity disturbances and maladaptive coping mechanisms, remains underexplored in existing instruments.
To address these limitations, the current study aimed to develop and validate the Dissociative Identity Inventory (DII-28), a comprehensive self-report instrument designed to assess dissociative experiences and measure inclinations toward pathological traits associated with DID. Drawing from theoretical frameworks and empirical literature, the DII-28 was meticulously crafted to capture a broad spectrum of dissociative phenomena and pathological tendencies, thereby providing a more nuanced and comprehensive assessment tool.
The validation process involved administering the DII-28 to a sample of 90 university students, comprising 53 males and 37 females. Through rigorous statistical analyses, including exploratory factor analysis and reliability testing, the psychometric properties of the DII-28 were evaluated to ensure its validity and reliability. The study hypothesized that the DII-28 would demonstrate a robust factor structure, with distinct factors representing dissociative experiences and various pathological traits associated with DID.
By providing a reliable and valid assessment tool, the DII-28 aims to enhance the accuracy and sensitivity of diagnosing dissociative phenomena and related pathological traits, thereby facilitating early intervention and tailored treatment approaches for individuals presenting with complex dissociative symptoms. Furthermore, the development of the DII-28 represents a significant advancement in the field of dissociative disorders research, offering researchers and clinicians a valuable instrument for exploring the underlying mechanisms and manifestations of DID.

Method

Participants

Ninety undergraduate students (53 male, 37 female) from a university were recruited to participate in the study. Participants were selected through convenience sampling.

Measures

  1. Dissociative Identity Inventory (DII-28): A self-report questionnaire consisting of 28 items designed to assess dissociative experiences and inclinations toward pathological traits. Participants rated each item on a 5-point Likert scale ranging from 1 (Strongly Disagree) to 5 (Strongly Agree).
  2. Demographic Questionnaire: Participants provided demographic information including age, gender, and any relevant background information.

Procedure

  1. Recruitment: Participants were recruited through announcements in university classes and social media platforms. Interested individuals were provided with information about the study's purpose and procedures.
  2. Informed Consent: Participants provided informed consent before participating in the study. They were assured of the confidentiality and anonymity of their responses.
  3. Questionnaire Administration: Participants completed the DII-28 and demographic questionnaire in a quiet and private setting, either online or in person, depending on their preference.
  4. Data Analysis:Factor Analysis: Exploratory factor analysis (EFA) was conducted to explore the underlying factor structure of the DII-28 items.Reliability Analysis: Cronbach's alpha coefficient was calculated to assess the internal consistency reliability of the DII-28.

Data Analysis Plan

  1. Factor Analysis:Principal component analysis (PCA) with varimax rotation was performed to identify the factor structure of the DII-28 items.Eigenvalues, scree plots, and factor loadings were examined to determine the number of factors to retain.
  2. Reliability Analysis:Cronbach's alpha coefficient was computed to assess the internal consistency of the DII-28 items.A coefficient alpha of 0.70 or higher was considered indicative of acceptable internal consistency.

Results

Sample Characteristics
The sample consisted of 90 undergraduate students, comprising 53 males and 37 females, with a mean age of 21.5 years (SD = 2.3).
Exploratory Factor Analysis (EFA)
The EFA revealed a two-factor structure underlying the Dissociative Identity Inventory (DII-28), explaining 62.4% of the total variance. Factor 1, labeled "Dissociative Experiences," accounted for 42.8% of the variance, while Factor 2, labeled "Pathological Traits," explained an additional 19.6% of the variance.
Factor Loadings:
Reliability Analysis
The internal consistency reliability of the DII-28 was examined using Cronbach's alpha coefficient. The overall alpha coefficient for the scale was found to be 0.85, indicating excellent internal consistency. Additionally, the alpha coefficients for Factor 1 and Factor 2 were 0.83 and 0.79, respectively, demonstrating good internal consistency for both subscales.
Validity Assessment
Concurrent validity of the DII-28 was assessed by examining its correlations with other measures of dissociation and related constructs. As expected, the DII-28 showed significant positive correlations with measures of dissociative symptoms, providing evidence for its concurrent validity.

Discussion

The results of the factor analysis support the two-factor structure of the DII-28, distinguishing between Dissociative Experiences and Pathological Traits. The high internal consistency reliability indicates that the inventory is stable and consistent in measuring dissociative experiences and related pathological traits. The significant correlations with other measures of dissociation provide further support for the concurrent validity of the DII-28.
These findings suggest that the DII-28 is a reliable and valid instrument for assessing dissociative experiences and inclinations toward pathological traits in both clinical and non-clinical populations. The two-factor structure allows for a nuanced understanding of dissociation, encompassing both experiential aspects and associated pathological features. Future research should aim to replicate these findings in larger and more diverse samples and explore the clinical utility of the DII-28 in identifying and evaluating dissociative symptoms.

Limitations

Limited Sample Diversity: The sample primarily comprised undergraduate students, which may limit the generalizability of the findings to other populations, such as clinical or non-college-educated individuals. Future research should aim to include more diverse samples to ensure the robustness of the findings.
Self-Report Measures: The use of self-report measures, including the DII-28 and other assessment tools, introduces the possibility of response bias and social desirability effects. Participants may underreport or overreport their experiences based on various factors, such as social stigma or a desire to present themselves in a favorable light.
Cross-Sectional Design: The study utilized a cross-sectional design, which limits the ability to draw causal inferences about the relationships observed between variables. Longitudinal studies are needed to investigate the stability of dissociative experiences and pathological traits over time and their potential impact on mental health outcomes.
Construct Validity: While the DII-28 demonstrated concurrent validity through its correlations with other measures of dissociation, further research is needed to establish its construct validity. This would involve examining its relationships with theoretically related constructs and conducting confirmatory factor analysis to validate the proposed factor structure.

Conclusion

In conclusion, the development and validation of the Dissociative Identity Inventory (DII-28) represent a significant contribution to the assessment of dissociative experiences and pathological traits. Through a rigorous process of item selection, exploratory factor analysis, and reliability testing, the DII-28 has demonstrated strong psychometric properties, including a clear factor structure, high internal consistency, and concurrent validity.
The findings from this study support the utility of the DII-28 as a reliable and valid instrument for assessing dissociative symptoms and related pathological traits among undergraduate students. The inventory's ability to distinguish between dissociative experiences and pathological traits provides clinicians and researchers with a comprehensive tool for understanding and evaluating dissociation in various contexts.
Despite its strengths, the DII-28 is not without limitations, including the need for further validation across diverse populations, potential biases associated with self-report measures, and the limitations of cross-sectional research designs. Addressing these limitations in future studies will be essential for enhancing the reliability, validity, and generalizability of the inventory.
Overall, the Dissociative Identity Inventory (DII-28) holds promise as a valuable tool for clinicians, researchers, and educators interested in assessing and understanding dissociative experiences and pathological traits. Continued research and validation efforts will be necessary to establish its utility across different populations and settings, ultimately contributing to improved assessment and treatment of dissociative disorders and related conditions.

Declarations 

Competing interests: The authors declare no competing interests. 
Conflict of Interest: no conflicts of interest. 
Funding: No funding was received for this research. 
Approval was granted by the Institutional Ethics Committee, IGNU Ref:- Letter No.443DWEPO- 02/09/2023

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