RESEARCH
The IDDQ is being developed through a structured international research programme.
The planned stages include:
development of an ICD-11-based item pool
review by international experts
an international Delphi study to identify the clearest and most clinically relevant items
Current stage
pilot testing and psychometric evaluation
clinical validation against comprehensive diagnostic assessments
translation and cultural adaptation studies
The final questionnaire will be shaped by expert consensus and empirical findings.
The item pool
An international group of clinicians, researchers, and experts in dissociative disorders has developed a comprehensive preliminary pool of potential questionnaire items. These items are based on the ICD-11 diagnostic framework, the scientific literature, existing assessment instruments, and clinical expertise.
The pilot item pool is intentionally broad and contains several alternative formulations for many symptoms. These items are not yet the final questionnaire. Through the international Delphi process, experts will evaluate which items are most relevant, clear, diagnostically specific, and suitable across different cultures and languages.
Length of the questionnaire
The Delphi study aims to identify approximately 10 core screening items; the final number will depend on the results of the Delphi process and subsequent psychometric validation.
The current development version contains a large item pool to ensure that all relevant symptom domains are adequately represented. The Delphi study and later psychometric analyses will be used to reduce this pool and identify a shorter final version with the best clinical and statistical performance.
The long-term aim is to create an instrument that is brief enough for routine use while still providing meaningful information about different dissociative disorder profiles.
Translation and international validation
Translations and cultural adaptations will require standardised procedures, including expert review, forward and backward translation, pilot testing, and psychometric validation.
Next steps and transparency
Following the Delphi study, the selected items will undergo further pilot testing, validation, and refinement. The long-term goal is to make the final questionnaire and its validated translations widely available for clinical and scientific use.
Information on ethics approvals, study registration, participating countries, publications, and collaboration opportunities will be published on this page as the project progresses.
Current studies
Recruiting
International Delphi Study
Experts evaluate proposed IDDQ items across structured rounds. Approx. 30 minutes per round.
Learn more