International Trauma Questionnaire (ITQ)

The International Trauma Questionnaire (ITQ) is an 18 question self-report measure focusing on the core features of Post Traumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). It was developed to be consistent with the organizing principles of the ICD-11.

The ITQ is designed for diagnosis and can discriminate PTSD from CPTSD by employing validated diagnostic rules. The scale has two major subscales with three symptom clusters in each:

Post Traumatic Stress Disorder (PTSD)

  • Re-experiencing
  • Avoidance
  • Sense of threat

Disturbances in self-organization (DSO)

  • Affective dysreglation
  • Negative self-concept
  • Disturbances in relationships

Disturbances in self-organization are important in the assessment and diagnosis of CPTSD.

The ITQ is useful in the assessment of adults who have experienced trauma and asks them to answer the questions in relation to a specific traumatic event.

Psychometric Properties

During the ITQ’s development, Hyland et al. (2017) evaluated the measure against the 11th version of the International Classification of Diseases (ICD-11) which proposed two related trauma diagnoses: Posttraumatic stress disorder (PTSD) and Complex PTSD (CPTSD). The study assessed the factorial validity of ICD-11 PTSD and CPTSD and provided the first test of the discriminant validity of these constructs is the ITQ.

Cloitre et al. (2018) established the optimal symptom indicators of PTSD and CPTSD by applying item response theory (IRT) analysis to data from a trauma‐exposed community sample (n = 1051) and a trauma‐exposed clinical sample (n = 247) from the United Kingdom.

Scoring and Interpretation 

There are two components of scoring and interpretation: Categorical scoring for the diagnosis of PTSD and CPTSD, and a dimensional component which measures symptom severity.

The diagnosis of PTSD is indicated based on the following criteria:

  • Question 1 or 2 = two or more (re-experiencing)
  • Question 3 or 4 = two or more (avoidance)
  • Question 5 or 6 = two or more (sense of current threat)
  • Question 7, 8 or 9 = two or more (PTSD functional impairment)

PTSD is indicated if the criteria for PTSD are met and CPTSD is NOT met.

The diagnosis of Complex PTSD (CPTSD) is indicated based on the following criteria:

  • Question 10 or 11 = two or more (affective dysregulation)
  • Question 12 or 13 = two or more (negative self-concept)
  • Question 14 or 15 = two or more (disturbances in relationships)
  • Question 16, 17 or 18 = two ore more (Disturbances in self-organisation impairment)

CPTSD is diagnosed if the criteria for PTSD are met AND criteria for CPTSD are met.

Dimensional scores from 0 to 24 are presented for the two major subscale.

  1. Post Traumatic Stress Disorder (PTSD) (sum of items 1 to 6)
  2. Disturbances in self-organization (DSO) (sum of items 10 to 15)

In addition, the four factors under each major subscale are presented (raw score from 0 to 8). Note that the functional impairment factors do not count towards the totals of the major subscales.

Each score is presented as a raw score and a scaled score. The scaled scores are between 0 and 10 and are calculated by dividing the raw score by the maximum possible score, times 100. The scaled scores are useful for comparison between symptom clusters as they are all scored out of 10.

The dimensional scores can be useful in tracking symptoms at the start, middle and end of treatment to ascertain the level of treatment response.

Developer

Cloitre, M., Shevlin M., Brewin, C.R., Bisson, J.I., Roberts, N.P., Maercker, A., Karatzias, T., Hyland, P. (2018). The International Trauma Questionnaire: Development of a self-report measure of ICD-11 PTSD and Complex PTSD. Acta Psychiatrica Scandinavica. DOI: 10.1111/acps.12956

References

Hyland, Shevlin, Brewin, Cloitre, Downes, Jumbe, Karatzias, Bisson, & Roberts. (2017). Validation of post-traumatic stress disorder (PTSD) and complex PTSD using the International Trauma Questionnaire. Acta Psychiatrica Scandinavica, 136(3), 313–322. https://doi.org/10.1111/acps.12771