Enhanced Skills Training in Affective and Interpersonal Regulation versus Treatment as Usual for ICD-11 Complex PTSD: A Pilot Randomised Controlled Trial (The RESTORE Trial).

INTRODUCTION: Complex PTSD (CPTSD) is a relatively new condition in ICD-11. This pilot randomised controlled trial aimed to compare a four-module intervention developed to target all symptoms of ICD-11 CPTSD, namely Enhanced Skills in Affective and Interpersonal Regulation (ESTAIR) with treatment as usual (TAU). The purpose of the study was to assess feasibility, safety, acceptability, and preliminary outcomes at the end of treatment and 3-month follow-up. METHODS: A total of N = 56 eligible veterans with CPTSD were randomised to either ESTAIR (n = 28) or TAU (n = 28). Linear mixed models were conducted to assess CPTSD severity, the primary outcome, as measured by the International Trauma Questionnaire (ITQ). RESULTS: Treatment dropout in ESTAIR and TAU was low and equivalent (18% vs. 11%; χ2 (1) = 1.19, p = 0.275), and study retention was high, supporting the feasibility of the study. No serious adverse effects and very few adverse effects occurred, none of which were deemed related to the study. ESTAIR provided significantly greater reduction in CPTSD severity across time for ITQ PTSD (p < 0.001) and DSO (p < 0.001) symptoms. CPTSD pre-to-post effect sizes for ESTAIR were large (PTSD d = 1.78; DSO d = 2.00). Remission of probable CPTSD diagnosis at post-treatment was substantially greater in ESTAIR compared to TAU with only 13.6% versus 84% (p < 0.001) retaining the diagnosis. CONCLUSION: A trial of ESTAIR versus TAU for the treatment of ICD-11 CPTSD indicates the potential efficacy of ESTAIR as well as its feasibility, safety, and acceptability.

Prevalence and correlates of ICD-11 prolonged grief disorder among adults living in Ukraine during the war with Russia.

BACKGROUND: Although high rates of bereavement are evident in war-affected populations, no study has investigated the prevalence and correlates of probable ICD-11 prolonged grief disorder (PGD) under these circumstances. METHODS: Participants were 2050 adults who participated in a nationwide survey exploring the effects of the Ukraine-Russia war on the daily lives and mental health of Ukrainian people. RESULTS: Of the total sample, 87.7% (n = 1797) of people indicated a lifetime bereavement. In the full sample, 11.4% met the diagnostic requirements for probable ICD-11 PGD, and amongst those with a lifetime bereavement, the conditional rate of probable ICD-11 PGD was 13.0%. Significant risk factors of ICD-11 PGD included the recent loss of a loved one (6 months to a year ago), being most affected by a partner or spouse's death, loved one dying in the war, no recent contact with the deceased prior to their death, and meeting depression and anxiety diagnostic requirements. CONCLUSION: The study reveals that a significant percentage of Ukrainian bereaved individuals have probable ICD-11 PGD, and identifying risk factors, particularly war-related losses, will aid in the development of intervention and prevention programs for bereaved adults.

ICD-11 post-traumatic stress disorder and complex post-traumatic stress disorder in mental health support-seeking former-serving Australian defence force veterans.

BACKGROUND: ICD-11 complex post-traumatic stress disorder is a more severe condition than post-traumatic stress disorder, and recent studies indicate it is more prevalent among military samples. In this study, we tested the psychometric properties of the International Trauma Questionnaire, assessed the relative prevalence rates of post-traumatic stress disorder and complex post-traumatic stress disorder in the sample population and explored relationships between complex post-traumatic stress disorder and post-traumatic stress disorder and a range of risk factors. METHODS: Survey participants (N = 189) were mental health support-seeking former-serving veterans of the Australian Defence Force (ADF) recruited from primary care. Confirmatory factor analysis was used to test the factorial validity of the International Trauma Questionnaire. RESULTS: The latent structure of the International Trauma Questionnaire was best represented by a two-factor second-order model consistent with the ICD-11 model of complex post-traumatic stress disorder. The International Trauma Questionnaire scale scores demonstrated excellent internal reliability. Overall, 9.1% (95% confidence interval = [4.8%, 13.5%]) met diagnostic requirements for post-traumatic stress disorder and an additional 51.4% (95% confidence interval = [44.0%, 58.9%]) met requirements for complex post-traumatic stress disorder. Those meeting diagnostic requirements for complex post-traumatic stress disorder were more likely to have served in the military for 15 years or longer, had a history of more traumatic life events and had the highest levels of depression, anxiety and stress symptoms. CONCLUSION: The International Trauma Questionnaire can effectively distinguish between post-traumatic stress disorder and complex post-traumatic stress disorder within primary care samples of Australian Defence Force veterans. A significantly greater proportion of Australian Defence Force veterans met criteria for complex post-traumatic stress disorder than post-traumatic stress disorder. Australian military mental health services should adopt the International Trauma Questionnaire to routinely screen for complex post-traumatic stress disorder and develop complex post-traumatic stress disorder specific interventions to promote recovery in Australian Defence Force veterans with complex post-traumatic stress disorder.

The International Grief Questionnaire (IGQ): A new measure of ICD-11 prolonged grief disorder.

Prolonged grief disorder (PGD) is included in the 11th version of the International Statistical Classification of Diseases and Related Health Problems (ICD-11). This study sought to test the validity and reliability of a new brief measure to screen for ICD-11 PGD-the International Grief Questionnaire (IGQ). The psychometric properties of the IGQ were tested using data collected from two bereaved samples of adults from the United Kingdom (n = 1,012) and Ireland (n = 1,011). Confirmatory factor analysis demonstrated that a correlated two-factor model best captured the latent dimensionality of the IGQ in both samples. Estimates of internal reliability were high, whereas the convergent and concurrent validity of the scale were supported through strong associations with external measures. Measurement invariance and differential item functioning testing showed no statistically significant difference in the latent structure of the IGQ nor the functioning of the IGQ items by age, sex, and nationality. For participants who were bereaved for more than 6 months, the rates of probable PGD derived from the IGQ were 10.9% and 15.3% for the Irish and U.K. samples, respectively. The IGQ is a brief, easy-to-use, self-report screening measure that captures all diagnostic criteria of PGD set forth in the ICD-11. Findings from this study provide initial support for the validity, measurement invariance, and reliability of the IGQ among two national samples.

Assessing self-reported prolonged grief disorder with "clinical checks": A proof of principle study.

Psychological assessment is commonly conducted using either self-report measures or clinical interviews; the former are quick and easy to administer, and the latter are more time-consuming and require training. Self-report measures have been criticized for producing higher estimates of symptom and disorder presence relative to clinical interviews, with the assumption being that self-report measures are prone to Type 1 error. Here, we introduce the use of "clinical checks" within an existing self-report measure. These are brief supplementary questions intended to clarify and confirm initial responses, similar to what occurs in a clinical interview. Clinical checks were developed for the items of the International Grief Questionnaire (IGQ), a self-report measure of ICD-11 prolonged grief disorder (PGD). Data were collected as part of a community survey of mental health in Ukraine. Individual symptom endorsements for the IGQ significantly decreased with the use of clinical checks, and the percentage of the sample that met the ICD-11 diagnostic requirements for PGD fell from 13.6% to 10.2%, representing a 24.8% reduction in cases. The value and potential broader application of clinical checks are discussed.

Severe Dissociative Experiences beyond Detachment in a Large Clinical Sample of Inpatients with Post-Traumatic Stress Disorder: Diagnostic and Treatment Implications.

INTRODUCTION: The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) contains a dissociative subtype of post-traumatic stress disorder (PTSD) characterized by depersonalization and derealization. Yet, there is evidence that dissociative symptoms in PTSD go beyond this kind of detachment dissociation and that some patients present with additional compartmentalization dissociation in the form of auditory-verbal hallucination, amnesia, and identity alteration. METHODS: Hence, in this study, we examined latent profiles of childhood trauma (Childhood Trauma Questionnaire), PTSD (Impact-of-Event Scale-Revised), and pathological dissociation (Dissociative Experiences Scale-Taxon; DES-T) in a large sample of severely traumatized inpatients with PTSD (N = 1,360). RESULTS: Results support a three-class solution of the latent profile analysis with a PTSD class, a dissociative subtype class, and a third class characterized by more complex and more severe dissociative symptoms. Importantly, in our inpatient sample of patients with severe PTSD, the latter class was found to be the most prevalent. Both the exploratory character of our retrospective analysis of clinical routine data and the use of the DES-T limit the generalizability of our findings, which require methodologically more rigorous replication. CONCLUSION: In severe PTSD, dissociative symptoms beyond detachment are highly prevalent. Diagnostic and treatment implications are discussed.

Development and validation of the caregiver-report version of the international depression questionnaire (IDQ-CG) and international anxiety questionnaire (IAQ-CG).

The International Depression Questionnaire (IDQ) and International Anxiety Questionnaire (IAQ) are self-report measures of ICD-11 single episode depressive disorder (DD) and generalised anxiety disorder (GAD). The present study sought to describe the development and psychometric evaluation of the caregiver-report versions of the IDQ and IAQ for children, referred to as the IDQ-CG and IAQ-CG, respectively. Participants were 639 parents living in Ukraine who provided data on themselves and one child in their household as part of "The Mental Health of Parents and Children in Ukraine Study: 2023 Follow-up" study. The latent structure of the IDQ-CG and IAQ-CG were tested using confirmatory factor analysis (CFA), composite reliability (CR) estimates were estimated, and convergent validity was assessed. Prevalence rates of probable ICD-11 DD and GAD were also estimated. CFA results indicated that the IDQ-CG and IAQ-CG were unidimensional, while the internal reliability of both scales was excellent. Convergent validity was established via associations with external measures of internalizing, externalizing, and attention problems as well as trauma exposure. Factors associated with increased IDQ-CG and IAQ-CG scores included pharmacological support for emotional or behavioural problems, delayed milestone development, being forced to move to another part of Ukraine, serious life disruption due to the war, and having experienced a bereavement. Of the total sample, 1.6% met diagnostic requirements for ICD-11 DD and 5.8% met diagnostic requirements for ICD-11 GAD. This study supports the psychometric properties of the IDQ-CG and IAQ-CG. These measures can be effectively used to identify young people in need of mental health support.

The psychological burden of bereavement in the general population of UK and Ireland.

This study examined the experiences of loss among bereaved adults, and the association between loss-related factors and mental health outcomes. Participants were 2023 bereaved adults from the United Kingdom and Ireland who completed measures of their bereavement experiences and symptoms of depression, anxiety, and somatization. The highest proportion of participants and those at greatest risk of meeting criteria for all disorders were those with less time since loss, who were in contact with the deceased every day or not at all in the year prior to their death, experienced sudden unnatural death, and those who lost a partner/spouse or a child. Age of the deceased was negatively correlated with meeting criteria for depression, anxiety, and somatization. Overall, depression, anxiety, and somatization were common in the bereaved population. Identifying key loss-related variables-such as time since bereavement and nature of death-will help target those needing urgent psychological support.

Is Dissociation a Fundamental Component of ICD-11 Complex Posttraumatic Stress Disorder?

ICD-11 Complex Posttraumatic Stress Disorder (CPTSD) is a disorder of six symptom clusters including reexperiencing, avoidance, sense of threat, affective dysregulation, negative self-concept, and disturbed relationships. Unlike earlier descriptions of complex PTSD, ICD-11 CPTSD does not list dissociation as a unique symptom cluster. We tested whether the ICD-11 CPTSD symptoms can exist independently of dissociation in a nationally representative sample of adults (N = 1,020) who completed self-report measures. Latent class analysis was used to identify unique subsets of people with distinctive symptom profiles. The best fitting model contained four classes including a "low symptoms" class (48.9%), a "PTSD" class (14.7%), a "CPTSD" class (26.5%), and a "CPTSD + Dissociation" class (10.0%). These classes were related to specific adverse childhood experiences, notably experiences of emotional and physical neglect. The "PTSD," "CPTSD," and "CPTSD + Dissociation" classes were associated with a host of poor health outcomes, however, the "CPTSD + Dissociation" class had the poorest mental health and highest levels of functional impairment. Findings suggest that ICD-11 CPTSD symptoms can occur without corresponding dissociative experiences, however, when CPTSD symptoms and dissociative experiences occur together, health outcomes appear to be more severe.

Distinguishing between ICD-11 complex post-traumatic stress disorder and borderline personality disorder: clinical guide and recommendations for future research.

Although complex post-traumatic stress disorder and borderline personality disorder are distinct disorders, there is confusion in clinical practice regarding the similarities between the diagnostic profiles of these conditions. We summarise the differences in the diagnostic criteria that are clinically informative and we illustrate these with case studies to enable diagnostic accuracy in clinical practice.

Functioning, symptom expression and risk along the psychosis continuum.

BACKGROUND: The psychosis continuum implies that subclinical psychotic experiences (PEs) can be differentiated from clinically relevant expressions since they are not accompanied by a 'need for care'. METHODS: Using data from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; N = 34 653), the current study examined variation in functioning, symptomology and aetiological risk across the psychosis phenotype [i.e. variation from (i) no PEs, 'No PEs' to (ii) non-distressing PEs, 'PE-Experienced Only' to (iii) distressing PEs, 'PE-Impaired' to (iv) clinically defined psychotic disorder, 'Diagnosed']. RESULTS: A graded trend was present such that, compared to those with no PEs, the Diagnosed group had the poorest functioning, followed by the PE-Impaired then PE-Experienced Only groups. In relation to symptom expression, the PE-Impaired group were more likely than the PE-Experienced Only and the Diagnosed groups to endorse most PEs. Predictors of group membership tended to vary quantitatively rather than qualitatively. Trauma, current mental health diagnoses (anxiety and depression) and drug use variables differentiated between all levels of the continuum, with the exception of the extreme end (PE-Impaired v. Diagnosed). Only a few variables distinguished groups at the upper end of the continuum: female sex, older age, unemployment, parental mental health hospitalisation and lower likelihood of having experienced physical assault. CONCLUSIONS: The findings highlight the importance of continuum-based interpretations of the psychosis phenotype and afford valuable opportunities to consider if and how impairment, symptom expression and risk change along the continuum.

Refuting the myth of a 'tsunami' of mental ill-health in populations affected by COVID-19: evidence that response to the pandemic is heterogeneous, not homogeneous.

BACKGROUND: The current study argues that population prevalence estimates for mental health disorders, or changes in mean scores over time, may not adequately reflect the heterogeneity in mental health response to the COVID-19 pandemic within the population. METHODS: The COVID-19 Psychological Research Consortium (C19PRC) Study is a longitudinal, nationally representative, online survey of UK adults. The current study analysed data from its first three waves of data collection: Wave 1 (March 2020, N = 2025), Wave 2 (April 2020, N = 1406) and Wave 3 (July 2020, N = 1166). Anxiety-depression was measured using the Patient Health Questionnaire Anxiety and Depression Scale (a composite measure of the PHQ-9 and GAD-7) and COVID-19-related posttraumatic stress disorder (PTSD) with the International Trauma Questionnaire. Changes in mental health outcomes were modelled across the three waves. Latent class growth analysis was used to identify subgroups of individuals with different trajectories of change in anxiety-depression and COVID-19 PTSD. Latent class membership was regressed on baseline characteristics. RESULTS: Overall prevalence of anxiety-depression remained stable, while COVID-19 PTSD reduced between Waves 2 and 3. Heterogeneity in mental health response was found, and hypothesised classes reflecting (i) stability, (ii) improvement and (iii) deterioration in mental health were identified. Psychological factors were most likely to differentiate the improving, deteriorating and high-stable classes from the low-stable mental health trajectories. CONCLUSIONS: A low-stable profile characterised by little-to-no psychological distress ('resilient' class) was the most common trajectory for both anxiety-depression and COVID-19 PTSD. Monitoring these trajectories is necessary moving forward, in particular for the ~30% of individuals with increasing anxiety-depression levels.

War exposure, posttraumatic stress disorder, and complex posttraumatic stress disorder among parents living in Ukraine during the Russian war.

BACKGROUND: High rates of posttraumatic stress disorder (PTSD) have been documented in war-affected populations. The prevalence of Complex PTSD (CPTSD) has never been assessed in an active war zone. Here, we provide initial data on war-related experiences, and prevalence rates of ICD-11 PTSD and CPTSD in a large sample of adults in Ukraine during the Russian war. We also examined how war-related stressors, PTSD, and CPTSD were associated with age, sex, and living location in Ukraine. METHOD: Self-report data were gathered from a nationwide sample of 2004 adult parents of children under 18 from the general population of Ukraine approximately 6 months after Russia's invasion. RESULTS: All participants were exposed to at least one war-related stressor, and the mean number of exposures was 9.07 (range = 1-26). Additionally, 25.9% (95% CI = 23.9%, 27.8%) met diagnostic requirements for PTSD and 14.6% (95% CI = 12.9%, 16.0%) met requirements for CPTSD. There was evidence of a strong dose-response relationship between war-related stressors and meeting criteria for PTSD and CPTSD. Participants who had the highest exposure to war-related stressors were significantly more likely to meet the requirements for PTSD (OR = 4.20; 95% CI = 2.96-5.95) and CPTSD (OR = 8.12; 95% CI = 5.11-12.91) compared to the least exposed. CONCLUSIONS: Humanitarian responses to the mental health needs of the Ukrainian population will need to take account of posttraumatic stress reactions. Education in diagnosing and treating PTSD/CPTSD, especially in the situation of a significant lack of human resources and continuing displacement of the population, is necessary.

Emotional control in selected somatic and psychiatric diseases.

THE AIM: was to assess the level of subjective control of emotional states among patients treated for dermatological and gastrointestinal somatic diseases compared to those with depressive and anxiety disorders. The results were related to the analyzed dimensions of emotion regulation in healthy subjects. MATERIALS AND METHODS: The reports of the conducted studies were compiled for a total of 310 people, including 120 patients diagnosed with a somatic disease (psoriasis, rosacea, irritable bowel syndrome, and gastroesophageal reflux), as well as 96 patients diagnosed with depressive disorders and 30 patients with anxiety disorders. The control group consisted of healthy subjects (64 individuals). To assess the psychological variables analyzed, the subjects completed the Emotion Regulation Questionnaire developed by J. Brzezinski. RESULTS: The study showed that the patients suffering from a chronic somatic symptom disorder, similarly to those treated for depression and anxiety disorders, differed from the healthy individuals in most aspects of emotional control. The patients with dermatological and gastrointestinal diseases differed statistically significantly from the patients with depression and the patients with anxiety disorders in relation to three dimensions of emotional control. Patients with a somatic disease are characterized by higher emotional and rational motivation, lower emotional resilience and lower emotional arousal. CONCLUSIONS: A chronic disease co-occurs with the emotional sphere of a person's daily functioning. Regardless of the diagnosis in terms of somatic disorders and mental illnesses, the way in which emotional states are controlled can be an important factor in the onset of the disease, coping with it as well as the treatment process.

Testing the latent structure of ICD-11 prolonged grief disorder symptoms in the U.K. adult population: An exploratory structural equation modeling approach.

The latent structure of ICD-11 prolonged grief disorder (PGD), as measured using the International Prolonged Grief Disorder Scale (IPGDS), was assessed in a large general population sample of bereaved adults from the United Kingdom. Data were derived from Wave 5 of the COVID-19 Psychological Research Consortium Study (C19PRC-UK). Exploratory structural equation modeling (ESEM) was used to assess the latent structure of the IPGDS. Identified factors were explored in relation to known correlates (i.e., gender, age of the bereaved, income, bereavement timeframe, age of the deceased) and functional impairment. Three factors-Loss, Emotional Numbing, and Emotional Reactivity-emerged in the best-fitting ESEM model, χ2 (92, N = 1,763) = 273.70, p < .001, CFI = .97, TLI = .96, RMSEA = .048, SRMR = .020. All factors were significantly associated with bereavement timeframe, ßs = -.15--.20, and age of the deceased, ßs = -.22--.31. Lower income predicted both Loss and Emotional Numbing; younger age of the bereaved predicted both Loss and Emotional Reactivity; and female gender was a unique predictor of Loss. Functional impairment was associated only with Emotional Numbing, ß = .89. The findings highlight the multidimensional structure of PGD. However, the patterns of factor/cross-factor loadings observed in the present study indicate that a "simple" structure was not attainable. Associations between factors and covariates attest to the discriminant validity of the factors, and the association between Emotional Numbing and functional impairment may afford clinicians an opportunity to better understand and target the most disruptive features of grief.

Investigating the latent structure of the International Trauma Questionnaire to assess ICD-11 posttraumatic stress disorder (PTSD) and complex PTSD in an adult civilian sample during the Ukraine war.

The symptom structure of ICD-11 posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) and the validity of the International Trauma Questionnaire (ITQ) are yet to be tested among civilians in an active war zone. The present investigation examined the factor structure of the ITQ, the internal consistency of observed scores, and their associations with demographic characteristics and war-related experiences using a nationwide sample of 2,004 adults from the general population of Ukraine approximately 6 months after the full-scale Russian invasion in 2022. Overall, rates of endorsement across all symptom clusters were high. The mean total number of war-related stressors reported was 9.07 (SD = 4.35, range: 1-26). Internal reliability was good for all six ITQ subscales, Cronbach's αs = .73-.88, and the correlated six-factor model was found to provide the best representation of the latent structure of the ITQ in the present sample based on fit indices. There was evidence of a dose-response relationship, with increasing scores on all symptom clusters associated with higher total reported war-related stressors.

Symptoms and levels of ICD-11 Prolonged Grief Disorder in a representative community sample of UK adults.

BACKGROUND: Prolonged Grief Disorder (PGD) is a new disorder included in ICD-11 (WHO, 2018). There is a growing body of literature surrounding the prevalence and correlates of ICD-11 PGD symptoms as assessed using various measures. This study was the first to assess levels of ICD-11 PGD symptoms as measured by the International Prolonged Grief Disorder Scale (IPGDS), a self-report scale directly aligned with the ICD-11 definition of PGD, among the United Kingdom adult general population, and identify correlates. METHOD: Participants included 2025 adults who participated in Wave 5 of the COVID-19 Psychological Research Consortium Study (C19PRC-UK). Prevalence rates of PGD were estimated based on two commonly used algorithms defined as 'strict' and 'moderate'. Sociodemographic, loss-related, and mental health correlates (i.e., anxiety, depression, mental health treatment seeking, loneliness) of strict and moderate PGD were then examined using multinomial logistic regressions. RESULTS: It was found that 2.4% (n = 43) of participants met probable caseness for PGD using the strict criteria while 7.9% (n = 140) met probable caseness for PGD using the moderate criteria. Multinomial logistic regression analysis results showed, as predicted, that income, time since bereavement, death of a child, religiosity, and depression were associated with both moderate and strict PGD. Correlates of moderate PGD included country of residence, urbanicity, younger age of bereaved, and loneliness. CONCLUSIONS: This study highlights that some symptoms of PGD are commonly reported in the general population, although relatively few meet the criteria for clinical significance. The routine assessment for PGD following a bereavement is discussed and the development of appropriate interventions are recommended.

Change in child mental health during the Ukraine war: evidence from a large sample of parents.

The ongoing war in Ukraine is expected to negatively impact the mental health of the country's population. This study aims to provide a preliminary estimate of the degree of change in the mental health problems of Ukrainian children following Russia's invasion in February 2022, and to identify the sociodemographic and war-related risk factors associated with these changes. A nationwide, opportunistic sample of 1238 parents reported on a single randomly chosen child within their household as part of The Mental Health of Parents and Children in Ukraine Study. Data were collected between July 15th and September 5th, 2022. Participants completed modified versions of the Pediatric Symptom Checklist (PSC-17) which was adapted to capture change in the frequency of symptoms since the beginning of the war. Parents reported increases across all 17 indicators of internalizing, externalizing, and attention problems of the PSC-17. Increased problems were most pronounced within the internalizing domain, with 35% of parents reporting that their child worried more since the beginning of the war. A number of individual, parental, and war-related factors were associated with increases across the three domains. Exposure to war trauma, pre-existing mental health problems, and child age were among the strongest predictors of change. This survey provides preliminary evidence that the Russian war on Ukraine has led to an increase in common mental health problems among children in the general population. Further research is required to determine the extent and sequela of this increase, and to develop intervention strategies for those most in need.

The development and initial validation of self-report measures of ICD-11 depressive episode and generalized anxiety disorder: The International Depression Questionnaire (IDQ) and the International Anxiety Questionnaire (IAQ).

BACKGROUND: The new International Classification of Diseases came into effect in 2022 (ICD-11; World Health Organization, 2022) and included updated descriptions and diagnostic rules for "Depressive Episode" and "Generalized Anxiety Disorder." No self-report measures align with these disorders so this study reports the development and initial validation of the "International Depression Questionnaire" (IDQ) and "International Anxiety Questionnaire" (IAQ). METHODS: Items were developed that aligned to the ICD-11 descriptions and their performance was assessed using data from a community sample (N = 2058) that was representative of the United Kingdom adult population. RESULTS: Item response theory models indicated that the two scales were unidimensional, and the items performed well in terms of difficulty and discrimination. Estimates of internal reliability were high. Based on ICD-11 derived diagnostic algorithms, 7.4% met requirements for ICD-11 Depressive Episode and 7.1% for Generalized Anxiety Disorder. CONCLUSIONS: The IDQ and the IAQ are short, easy to use, self-report measures aligned to the new and updated ICD-11 diagnostic descriptions. This study provides initial evidence that the scales produce scores that are reliable and valid.

Assessing the validity and reliability of the International Anxiety Questionnaire and the International Depression Questionnaire in two bereaved national samples.

The International Anxiety Questionnaire (IAQ) and International Depression Questionnaire (IDQ) are self-report measures of ICD-11 Generalized Anxiety Disorder (ICD-11 GAD) and ICD-11 Single Episode Depressive Disorder (ICD-11 DD). This study tested the psychometric properties of these scales in two samples of bereaved adults from the United Kingdom and the Republic of Ireland. Confirmatory factor analysis (CFA) was used to test the combined dimensionality and measurement invariance of the IAQ and IDQ across the United Kingdom (n = 1012) and Irish (n = 1011) samples. Differential item functioning (DIF) was tested using multiple indicator multiple cause (MIMIC) modelling while convergent validity was also assessed. CFA results supported a correlated two-factor model in both samples. The MIMIC model showed that the IDQ item "Had recurrent thoughts of death or suicide" showed DIF and the effect was small. Internal reliability of the scales were high and convergent validity was supported. The prevalence of ICD-11 GAD was 18.6% and 16.1% and ICD-11 DD was 13.8% and 10.5% in the United Kingdom and Irish samples, respectively. Findings of the study provide support for the validity, measurement invariance, and reliability of the IAQ and IDQ among two bereaved national samples.