International Trauma Questionnaire (ITQ)

The International Trauma Questionnaire (ITQ) is based on the International Classification of Diseases 11 (ICD-11) model of trauma-related diagnoses, offering a clinically relevant tool for identifying PTSD and Complex PTSD (CPTSD) symptoms.

Example ITQ Items

The ITQ has two subscales with three symptom clusters in each.

Post Traumatic Stress Disorder (PTSD)

• Re-experiencing – intrusive memories, flashbacks, or nightmares where the traumatic event feels as though it is happening again in the present
• Avoidance – deliberate efforts to avoid thoughts or feelings and situations, people, or places that evoke memories of the traumatic event
• Sense of threat – persistent feelings of being in danger, manifesting as hypervigilance (being “on guard”) and heightened startle response

Disturbances in Self Organization (DSO)

• Affective dysregulation – difficulties managing emotions, including heightened emotional reactivity or emotional numbing
• Negative self-concept – persistent negative beliefs about oneself, including feelings of worthlessness or viewing oneself as a failure
• Disturbances in relationships – difficulties in forming and maintaining close relationships, feeling distant or cut off from others, and finding it challenging to stay emotionally close to people

The ITQ reliably discriminates between people with PTSD alone and those with CPTSD. Individuals with PTSD alone score above the threshold on the PTSD symptom clusters without meeting criteria for DSO, whereas those with CPTSD score above the threshold on both PTSD and DSO subscales. The ITQ also assesses functional impairments associated with PTSD and DSO, ensuring a comprehensive assessment of trauma-related symptoms and their impact on functioning.

Scores on the ITQ indicate the presence and severity of PTSD and/or DSO symptoms and associated functional impairments. The ITQ can be used by qualified professionals, such as psychologists, as part of a comprehensive diagnostic assessment process for PTSD and CPTSD and for monitoring treatment progress over time.

Compared to other PTSD assessment tools, such as the PTSD Checklist for DSM-5 (PCL-5), the ITQ has a distinct advantage in its inclusion of CPTSD.

Research suggests that CPTSD is experienced by approximately 40-50% of individuals who meet criteria for a trauma-related disorder (Karatzias et al., 2017). People with CPTSD tend to experience greater functional impairment compared to those with PTSD alone, affecting their relationships, work capabilities, and overall quality of life.

• PTSD and CPTSD are often associated with different types of traumatic experiences:
• PTSD is frequently linked to single-event traumas, such as car accidents, natural disasters, or assaults.

CPTSD is more commonly associated with prolonged, repeated or accumulated interpersonal trauma, such as chronic childhood abuse, neglect or domestic violence (Karatzias et al., 2017).

By differentiating between PTSD and CPTSD, the ITQ helps qualified professionals identify the distinct symptom profiles associated with different trauma experiences. Individuals with CPTSD may benefit from treatment approaches that address not only the core PTSD symptoms but also difficulties with emotional regulation and self-identity. This differentiation allows clinicians to develop more tailored treatment plans based on the specific presentation of trauma-related symptoms.

The International Trauma Questionnaire (ITQ) has two subscales:

• Post Traumatic Stress Disorder (PTSD) – assesses the core symptoms of PTSD according to the ICD-11, focusing on intrusive re-experiencing, deliberate avoidance, and persistent sense of threat.
• Disturbances in Self Organization (DSO) – assesses the additional symptom clusters that, together with PTSD symptoms, constitute Complex PTSD (CPTSD), and which reflect pervasive psychological disturbances that typically arise following prolonged or repeated traumatic experiences

It includes six items measuring PTSD symptoms from three symptom clusters:

• Re-experiencing (Items 1 and 2) – assesses intrusive memories, flashbacks, or nightmares where the traumatic event feels as though it is happening again in the present moment, rather than being remembered as a past event
• Avoidance (Items 3 and 4) – measures deliberate efforts to avoid internal reminders (thoughts, feelings, physical sensations) and external reminders (people, places, conversations, objects, activities, situations) that evoke memories of the traumatic event
• Sense of threat (Items 5 and 6) – evaluates persistent feelings of current danger, manifesting as hypervigilance (being “on guard” or watchful) and heightened startle response (being jumpy or easily startled)

It also includes six items measuring DSO symptoms from three symptom clusters:

• Affective dysregulation (Items 10 and 11) – measures difficulties managing emotions, including heightened emotional reactivity (difficulty calming down when upset) and emotional numbing (feeling emotionally shut down or disconnected from feelings)
• Negative self-concept (Items 12 and 13) – assesses persistent negative beliefs about oneself, including feelings of worthlessness and viewing oneself as a failure, reflecting a diminished sense of value or identity
• Disturbances in relationships (Items 14 and 15) – evaluates difficulties in forming and maintaining close relationships, feeling distant or cut off from others, and finding it challenging to stay emotionally close to people

The PTSD and DSO subscales are each accompanied by three items measuring associated functional impairments in the domains of social, occupational, and other important areas of life.

• PTSD related functional impairment (Items 7, 8, and 9) – measures the impact of PTSD symptoms on relationships, social life, work capabilities, and other important areas of life, indicating how significantly these symptoms disrupt daily functioning
• DSO related functional impairment (Items 16, 17, and 18) – measures the impact of DSO symptoms on relationships, social life, work capabilities, and other important areas of life, indicating how significantly these disturbances disrupt daily functioning

Each item is rated on a 5-point Likert-type scale from 0 to 4.

The scoring approach uses dichotomous scoring for diagnostic purposes and dimensional scoring for symptom severity.

Dichotomous Scoring

A score of 2 (Likert = “Moderately”) or higher on a symptom or functional impairment item indicates the presence (i.e., endorsement) of that symptom or impairment.

PTSD is indicated if:

• at least one symptom is present from each PTSD symptom cluster, and
• there is at least one functional impairment associated with these PTSD symptoms.

Complex PTSD (CPTSD) is indicated if:

• at least one symptom is present from each PTSD symptom cluster,
• there is at least one functional impairment associated with these PTSD symptoms,
• at least one symptom is present from each DSO symptom cluster, and
• there is at least one functional impairment associated with these DSO symptoms.

A person may receive a diagnosis of PTSD or CPTSD, but not both.

Dimensional Scoring

• The PTSD symptom severity score is the sum of items 1 to 6 and ranges from 0 to 24.
• The DSO symptom severity score is the sum of items 10 to 15 and ranges from 0 to 24.

The respondent’s scores are presented as raw scores and as percentiles based on normative data for trauma-exposed adults, contextualising their scores relative to the typical scores of adults in this normative sample. For example, the 50th percentile represents the typical level of symptom severity for an adult who has been exposed to trauma (i.e., “Mild”), while scores on the 90th percentile fall within the top 10% and are considered “Severe”.

Qualitative descriptors categorise the respondent’s scores based on specific ranges of percentiles.

• “Minimal” – Below the 25th percentile (subscale score between 0 and 3)
• “Mild” – 25th to 50th percentile (subscale score between 4 and 6)
• “Moderate” – 51st to 75th percentile (subscale score between 7 and 10)
• “Severe” – 76th to 95th percentile (subscale score between 11 and 16)
• “Very Severe” – Above the 95th percentile (subscale score between 17 and 24)

A diagnostic criteria descriptor also accompanies each score, indicating whether diagnostic criteria for PTSD and DSO symptoms are met, and whether specific symptom clusters and functional impairments are present, according to the dichotomous scoring threshold. CPTSD is indicated if the diagnostic criteria descriptor says “Criteria met” for both the PTSD subscale and the DSO subscale.

On first administration, graphs are presented showing the respondent’s scores as percentiles based on normative data for trauma-exposed adults (Baker et al., 2025). A graph is also presented comparing the respondent’s PTSD and DSO symptom severity scores to two samples: (1) the normative sample of trauma-exposed adults; and (2) a diagnostic sample. For the PTSD symptom severity score, this diagnostic sample consists of adults meeting the ITQ’s criteria for PTSD. For DSO symptom severity scores, the diagnostic sample consists of adults meeting the ITQ’s criteria for CPTSD. Shaded areas correspond to scores between the 25th and 75th percentile. This graph contextualises the respondent’s scores relative to typical symptom severity levels in these samples.

If administered more than once, longitudinal graphs are presented for the respondent’s raw PTSD and DSO symptom severity scores, which is useful for monitoring any changes in symptom severity over time and treatment progress and outcomes. A meaningful change in PTSD symptom severity is defined as a change of 6 or more points in the PTSD symptom severity score, and a meaningful change in DSO symptom severity is defined as a change of 7 or more points in the DSO symptom severity score, based on Reliable Change Index (RCI) calculations (i.e., a 6-7 or more point decrease indicates significant improvement; a 6-7 or more point increase indicates significant deterioration; and less than a 6-7 point change indicates no significant change).

The International Trauma Questionnaire (ITQ) has been extensively validated across diverse populations, demonstrating strong reliability and validity as a measure of ICD-11 Post-Traumatic Stress Disorder (PTSD) and Complex PTSD (CPTSD). It facilitates differential diagnosis between PTSD and CPTSD by capturing both PTSD and Disturbances in Self Organization (DSO) symptoms together with associated functional impairment.

Confirmatory factor analysis (CFA) has consistently supported this two-factor second-order structure (i.e., PTSD and DSO). The latent structure of the ITQ has been replicated across multiple studies, showing excellent model fit for trauma-exposed clinical and community samples (Cloitre et al., 2018; Hyland et al., 2017, 2024).

The ITQ has demonstrated excellent internal consistency, with high composite reliability scores for the two factors (subscales). Studies have reported Cronbach’s alpha values exceeding 0.90 for both subscales, indicating robust reliability (Cloitre et al., 2018; Hyland et al., 2017).

The ITQ demonstrates strong convergent validity, with PTSD symptom scores correlating highly with other established measures of PTSD, such as the PTSD Checklist for DSM-5 (PCL-5) (Cloitre et al., 2021). The PTSD and DSO subscales also show distinct associations with external variables:

• PTSD symptoms are strongly linked to panic disorder and generalized anxiety disorder (GAD).
• DSO symptoms uniquely predict negative trauma-related beliefs, distress tolerance deficits, and major depressive disorder (MDD) (Hyland et al., 2017).

These findings support the discriminant validity of PTSD and CPTSD symptomatology as measured by the ITQ.

The ITQ has been validated as a sensitive measure of treatment-related changes in symptom severity. Research with clinical populations, including military veterans, has demonstrated that ITQ scores significantly decline following psychological interventions (Cloitre et al., 2021).

Studies have also shown that the ITQ’s psychometric properties remain stable across diverse cultural groups and in multiple languages, reinforcing its validity for use in trauma-exposed populations worldwide (Hyland et al., 2024).

Thus, the ITQ demonstrates strong psychometric properties, including robust reliability, validity, and sensitivity to change, as well as cross-cultural and multilingual applicability. By assessing PTSD and DSO symptoms together with associated functional impairment, it has become the most widely used tool for the assessment and differential diagnosis of PTSD and CPTSD in clinical settings (Sarr et al., 2024).

Percentiles for normative and diagnostic samples, developed by NovoPsych, are presented in NovoPsych’s review of the ITQ (Baker et al., 2025), which includes detailed information about the composition of these reference samples.

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