SDQ-20

Overview

General Information

The Somatoform Dissociation Questionnaire (SDQ-20) is a self-report measure designed to assess somatoform dissociation, which refers to physical symptoms that are a manifestation of dissociative processes. Developed by Nijenhuis, Spinhoven, Van Dyck, Van der Hart, and Vanderlinden in 1996, the SDQ-20 is used in both clinical and research settings to identify and evaluate the severity of somatoform dissociation. It is suitable for individuals aged 18 and older and is often utilized in the context of trauma and dissociation studies.

Structure and Content

The SDQ-20 consists of 20 items that describe various somatoform dissociative symptoms. Respondents are asked to rate each item based on how often they have experienced the symptom in the past year. The responses are measured on a 5-point Likert scale ranging from 1 (never) to 5 (very often).

Applications

• Clinical Use: The SDQ-20 is used by clinicians to screen for somatoform dissociation, aiding in the diagnosis and treatment planning for individuals with trauma-related disorders and somatoform conditions.
• Research Use: Researchers employ the SDQ-20 to study the prevalence and characteristics of somatoform dissociation in different populations, as well as the relationship between somatoform dissociation and other psychological constructs.

Psychometric Properties

The SDQ-20 has demonstrated strong psychometric properties, ensuring its reliability and validity as a measure of somatoform dissociation.

Reliability

• Internal Consistency: The SDQ-20 exhibits high internal consistency, with Cronbach's alpha coefficients typically exceeding 0.90. This indicates that the items on the questionnaire reliably measure the same construct.
• Test-Retest Reliability: The SDQ-20 has shown good test-retest reliability, suggesting that it provides stable and consistent results over time.

Validity

• Construct Validity: The SDQ-20 has been validated through factor analyses, confirming its ability to measure the distinct construct of somatoform dissociation. It correlates well with other established measures of dissociation and trauma-related symptoms.
• Criterion Validity: The SDQ-20 effectively differentiates between individuals with high and low levels of somatoform dissociation, demonstrating its utility in identifying those experiencing significant dissociative symptoms.

Benefits

The SDQ-20 offers several advantages for clinicians and researchers:

• Comprehensive Assessment: Despite its brevity, the SDQ-20 provides a thorough evaluation of somatoform dissociative symptoms.
• Ease of Use: The questionnaire is straightforward to administer and score, making it practical for both clinical and research applications.
• Versatility: The SDQ-20 is suitable for use in a variety of settings and with diverse populations, enhancing its utility as a screening and assessment tool.

Conclusion

The Somatoform Dissociation Questionnaire (SDQ-20) is a valuable tool for assessing somatoform dissociation. Its strong psychometric properties, ease of use, and applicability in different settings make it an essential resource for clinicians and researchers. By providing a comprehensive evaluation of somatoform dissociative symptoms, the SDQ-20 contributes to better understanding, diagnosing, and managing trauma-related conditions, ultimately supporting effective interventions and therapeutic outcomes.