Development of self-report scales measuring collaborative vs. directive support: Assessing beliefs and behaviors in carers of adults with eating disorders.

Collaboration is more acceptable and likely to produce favorable outcomes when providing care to individuals with eating disorders compared to directive care. We developed two self-report instruments that assess the extent to which carers (e.g., family, friends) of individuals with eating disorders provide collaborative vs. directive support (Support Behaviors Scale; SBH) and the extent to which carers believe that such approaches are helpful (Support Beliefs Scale; SBL). Participants were mothers, fathers, partners, friends and siblings (N=141) of eating disorder patients in hospital or residential treatment. Confirmatory factor analyses were used to test measurement models comprising collaborative and directive approaches identified in previous research. A 19-item three-factor model exhibited best fit for each scale and included three distinct caregiving approaches: two that were collaborative (encouraging, concerned), and one that was directive. The scales exhibited acceptable internal consistency. Reported caregiving behaviors (SBH) were correlated with beliefs about caregiving (SBL). The scales can be used to assess caregiving stance and outcomes for interventions aimed at promoting collaboration in carers.

A randomized controlled trial of attention modification for social anxiety disorder.

Social Anxiety Disorder (SAD) models implicate social threat cue vigilance (i.e., attentional biases) in symptom development and maintenance. A modified dot-probe protocol has been shown to reduce SAD symptoms, in some but not all studies, presumably by modifying an attentional bias. The current randomized controlled trial was designed to replicate and extend such research. Participants included treatment-seeking adults (n = 108; 58% women) who met diagnostic criteria for SAD. Participants were randomly assigned to a standard (i.e., control) or modified (i.e., active) dot-probe protocol condition and to participate in-lab or at home. The protocol involved twice-weekly 15-min sessions, for 4 weeks, with questionnaires completed at baseline, post-treatment, 4-month follow-up, and 8-month follow-up. Symptom reports were assessed with repeated measures mixed hierarchical modeling. There was a main effect of time from baseline to post-treatment wherein social anxiety symptoms declined significantly (p < .05) but depression and trait anxiety did not (p > .05). There were no significant interactions based on condition or participation location (ps > .05). Reductions were maintained at 8-month follow-up. Symptom reductions were not correlated with threat biases as indexed by the dot-probe task. The modified and standard protocol both produced significant sustained symptom reductions, whether administered in-lab or at home. There were no robust differences based on protocol type. As such, the mechanisms for benefits associated with modified dot-probe protocols warrant additional research.

Types and Number of Traumas Associated With Suicidal Ideation and Suicide Attempts in PTSD: Findings From a U.S. Nationally Representative Sample.

Posttraumatic stress disorder (PTSD) is associated with suicidal ideation and suicide attempt; however, research has largely focused on specific samples and a limited range of traumas. We examined suicidal ideation and suicide attempt relating to 27 traumas within a nationally representative U.S. sample of individuals with PTSD. Data were from the National Epidemiologic Survey of Alcohol and Related Conditions (N = 34,653). Participants were assessed for lifetime PTSD and trauma history, suicidal ideation, and suicide attempt. We calculated the proportion of individuals reporting suicidal ideation or suicide attempt for each trauma and for the number of unique traumas experienced. Most traumas were associated with greater suicidal ideation and suicide attempt in individuals with PTSD compared to individuals with no lifetime trauma or with lifetime trauma but no PTSD. Childhood maltreatment, assaultive violence, and peacekeeping traumas had the highest rates of suicidal ideation (49.1% to 51.9%) and suicide attempt (22.8% to 36.9%). There was substantial variation in rates of suicidal ideation and suicide attempt for war and terrorism-related traumas. Multiple traumas increased suicidality, such that each additional trauma was associated with an increase of 20.1% in rate of suicidal ideation and 38.9% in rate of suicide attempts. Rates of suicidal ideation and suicide attempts varied markedly by trauma type and number of traumas, and these factors may be important in assessing and managing suicidality in individuals with PTSD.

Developing scales measuring disorder-specific intolerance of uncertainty (DSIU): a new perspective on transdiagnostic.

Intolerance of uncertainty (IU) is a construct of growing prominence in literature on anxiety disorders and major depressive disorder. Existing measures of IU do not define the uncertainty that respondents perceive as distressing. To address this limitation, we developed eight scales measuring disorder-specific intolerance of uncertainty (DSIU) relating to various anxiety disorders and major depressive disorder. We used exploratory factor analysis and item characteristic curves in two large undergraduate samples (Ns=627 and 628) to derive eight three-item DSIU scales (24 items total) that exhibited excellent psychometric properties. Confirmatory factor analysis supported the factor structures of the scales and the transdiagnostic nature of IU. Each scale predicted unique variance in its respective symptom measure beyond a traditional measure of IU. DSIU represents a theoretically proximal and causal intermediary between known vulnerability factors and disorder symptomatology. The DSIU scales can be used to advance theories of psychopathology and inform case conceptualization and treatment planning.

Cultural-based biases of the GAD-7.

The GAD-7 is a popular measure of generalized anxiety disorder (GAD) symptoms that has been used across many cultural groups. Existing evidence demonstrates that the prevalence of GAD varies across self-identified ethnic/cultural groups, a phenomenon that some researchers attribute to cross-cultural measurement error rather than to actual differences in rates of GAD. Nonetheless, the effect of culture on factor structure and response patterns to the GAD-7 have not been examined and could result over- or under-estimated GAD-7 scores across different cultural groups. The current investigation assessed the factor structure of the GAD-7 in White/Caucasian, Hispanic, and Black/African American undergraduates and tested for cultural-based biases. A modified one-factor model exhibited good fit across subsamples. Results revealed that Black/African American participants with high GAD symptoms scored lower on the GAD-7 than other participants with similar GAD symptoms. Results highlight the need for culturally sensitive GAD screening tools.

Imagery enhancements increase the effectiveness of cognitive behavioural group therapy for social anxiety disorder: a benchmarking study.

Emerging evidence suggests that imagery-based techniques may enhance the effectiveness of traditional verbal-linguistic cognitive interventions for emotional disorders. This study extends an earlier pilot study by reporting outcomes from a naturalistic trial of an imagery-enhanced cognitive behavioural group therapy (IE-CBGT, n = 53) protocol for social anxiety disorder (SAD), and comparing outcomes to historical controls who completed a predominantly verbally-based group protocol (n = 129). Patients were consecutive referrals from health professionals to a community clinic specialising in anxiety and mood disorders. Both treatments involved 12, two-hour group sessions plus a one-month follow-up. Analyses evaluated treatment adherence, predictors of dropout, treatment effect sizes, reliable and clinically significant change, and whether self-reported tendencies to use imagery in everyday life and imagery ability predicted symptom change. IE-CBGT patients were substantially more likely to complete treatment than controls (91% vs. 65%). Effect sizes were very large for both treatments, but were significantly larger for IE-CBGT. A higher proportion of the IE-CBGT patients achieved reliable change, and better imagery ability was associated with larger symptom change. Outcomes compared very favourably to published group and individual treatments for SAD, suggesting that IE-CBGT may be a particularly effective and efficient mode of treatment delivery.

Do people with and without medical conditions respond similarly to the short health anxiety inventory? An assessment of differential item functioning using item response theory.

OBJECTIVE: Individuals with medical conditions are likely to have elevated health anxiety; however, research has not demonstrated how medical status impacts response patterns on health anxiety measures. Measurement bias can undermine the validity of a questionnaire by overestimating or underestimating scores in groups of individuals. We investigated whether the Short Health Anxiety Inventory (SHAI), a widely-used measure of health anxiety, exhibits medical condition-based bias on item and subscale levels, and whether the SHAI subscales adequately assess the health anxiety continuum. METHODS: Data were from 963 individuals with diabetes, breast cancer, or multiple sclerosis, and 372 healthy individuals. Mantel-Haenszel tests and item characteristic curves were used to classify the severity of item-level differential item functioning in all three medical groups compared to the healthy group. Test characteristic curves were used to assess scale-level differential item functioning and whether the SHAI subscales adequately assess the health anxiety continuum. RESULTS: Nine out of 14 items exhibited differential item functioning. Two items exhibited differential item functioning in all medical groups compared to the healthy group. In both Thought Intrusion and Fear of Illness subscales, differential item functioning was associated with mildly deflated scores in medical groups with very high levels of the latent traits. Fear of Illness items poorly discriminated between individuals with low and very low levels of the latent trait. CONCLUSIONS: While individuals with medical conditions may respond differentially to some items, clinicians and researchers can confidently use the SHAI with a variety of medical populations without concern of significant bias.

Latent classes of nonresponders, rapid responders, and gradual responders in depressed outpatients receiving antidepressant medication and psychotherapy.

BACKGROUND: We used growth mixture modeling (GMM) to identify subsets of patients with qualitatively distinct symptom trajectories resulting from treatment. Existing studies have focused on 12-week antidepressant trials. We used data from a concurrent antidepressant and psychotherapy trial over a 6-month period. METHOD: Eight hundred twenty-one patients were randomized to receive either fluoxetine or tianepine and received cognitive-behavioral therapy, supportive therapy, or psychodynamic therapy. Patients completed the Montgomery-Åsberg depression rating scale (MADRS) at the 0, 1, 3, and 6-month periods. Patients also completed measures of dysfunctional attitudes, functioning, and personality. GMM was conducted using MADRS scores and the number of growth classes to be retained was based on the Bayesian information criterion. RESULTS: Criteria supported the presence of four distinct latent growth classes representing gradual responders of high severity (42% of sample), gradual responders of moderate severity (31%), nonresponders (15%), and rapid responders (11%). Initial severity, greater use of emotional coping strategies, less use of avoidance coping strategies, introversion, and less emotional stability predicted nonresponder status. Growth classes were not associated with different treatments or with proportion of dropouts. CONCLUSIONS: The longer time period used in this study highlights potential overestimates of nonresponders in previous research and the need for continued assessments. Our findings demonstrate distinct growth trajectories that are independent of treatment modality and generalizable to most psychotherapy patients. The correlates of class membership provide directions for future studies, which can refine methods to predict likely nonresponders as a means to facilitate personalized treatments.

Secondary Psychometric Examination of the Dimensional Obsessive-Compulsive Scale: Classical Testing, Item Response Theory, and Differential Item Functioning.

The Dimensional Obsessive-Compulsive Scale (DOCS) is a promising measure of obsessive-compulsive disorder (OCD) symptoms but has received minimal psychometric attention. We evaluated the utility and reliability of DOCS scores. The study included 832 students and 300 patients with OCD. Confirmatory factor analysis supported the originally proposed four-factor structure. DOCS total and subscale scores exhibited good to excellent internal consistency in both samples (α = .82 to α = .96). Patient DOCS total scores reduced substantially during treatment (t = 16.01, d = 1.02). DOCS total scores discriminated between students and patients (sensitivity = 0.76, 1 - specificity = 0.23). The measure did not exhibit gender-based differential item functioning as tested by Mantel-Haenszel chi-square tests. Expected response options for each item were plotted as a function of item response theory and demonstrated that DOCS scores incrementally discriminate OCD symptoms ranging from low to extremely high severity. Incremental differences in DOCS scores appear to represent unbiased and reliable differences in true OCD symptom severity.

How do elements of a reduced capacity to withstand uncertainty relate to the severity of health anxiety?

Intolerance of uncertainty (IU)--a multidimensional cognitive vulnerability factor--is associated with a variety of anxiety disorders and health anxiety (HA). To date, few studies have assessed whether IU dimensions (prospective and inhibitory IU) are differentially associated with HA and whether their contributions are independent of anxiety sensitivity (AS). This study addressed these issues using independent community (n = 155; 81% women) and undergraduate (n = 560; 86% women) samples. Results indicated that prospective IU, but not inhibitory IU, had significant positive associations with HA in community dwellers and undergraduate students. AS somatic and cognitive concerns were also significant predictors among both samples. In addition, severity of IU dimensions among individuals reporting elevated HA were compared against individuals diagnosed with generalized anxiety disorder, social anxiety disorder, panic disorder, and obsessive-compulsive disorder. Results indicated minimal differences between those with elevated HA and each of the anxiety disorder diagnoses. Findings lend support to the unique transdiagnostic nature of IU and support commonalities between HA and anxiety disorders.

Comparing short forms of the Social Interaction Anxiety Scale and the Social Phobia Scale.

The Social Interaction Anxiety Scale (SIAS) and the Social Phobia Scale (SPS; Mattick & Clarke, 1998) are companion scales developed to measure anxiety in social interaction and performance situations, respectively. The measures have strong discriminant and convergent validity; however, their factor structures remain debated, and furthermore, the combined administration length (i.e., 39 items) can be prohibitive for some settings. There have been 4 attempts to assess the factor structures of the scales and reduce the item content: the 14-item Social Interaction Phobia Scale (SIPS; Carleton et al., 2009), the 12-item SIAS-6/SPS-6 (Peters, Sunderland, Andrews, Rapee, & Mattick, 2012), the 21-item abbreviated SIAS/SPS (ASIAS/ASPS; Kupper & Denollet, 2012), and the 12-item Readability SIAS and SPS (RSIAS/RSPS; Fergus, Valentiner, McGrath, Gier-Lonsway, & Kim, 2012). The current study compared the short forms on (a) factor structure, (b) ability to distinguish between clinical and non-clinical populations, (c) sensitivity to change following therapy, and (d) convergent validity with related measures. Participants included 3,607 undergraduate students (55% women) and 283 patients with social anxiety disorder (43% women). Results of confirmatory factor analyses, sensitivity analyses, and correlation analyses support the robust utility of items in the SIPS and the SPS-6 and SIAS-6 relative to the other short forms; furthermore, the SIPS and the SPS-6 and SIAS-6 were also supported by convergent validity analyses within the undergraduate sample. The RSIAS/RSPS and the ASIAS/ASPS were least supported, based on the current results and the principle of parsimony. Accordingly, researchers and clinicians should consider carefully which of the short forms will best suit their needs.

Anxiety disorders are independently associated with suicide ideation and attempts: propensity score matching in two epidemiological samples.

BACKGROUND: Research suggests that suicidal behavior in individuals with anxiety disorders is attributable to co-occurring risk factors, such as depression. We argue that these conclusions are founded primarily in statistical adjustments that may obscure independent associations. We explored independent associations between specific anxiety disorders and suicide attempts and ideation by means of propensity score matching, a process that simulates a case-control study by creating matched groups that differ in group status (e.g., diagnosis of a specific anxiety disorder) but that are statistically equivalent on observed covariates. METHODS: We made use of the National Comorbidity Survey Replication (NCS-R) and the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), which include a total of 43,935 adults. Diagnoses included agoraphobia without panic disorder, generalized anxiety disorder, panic disorder with or without agoraphobia, posttraumatic stress disorder, social anxiety disorder, and specific phobia. RESULTS: Each anxiety disorder was (95% confidence intervals) associated with increased odds of lifetime suicide attempts (odds ratios 3.57-6.64 [NCS-R], 3.03-7.00 [NESARC]) and suicidal ideation (odds ratios 2.62-4.87 [NCS-R], 3.34-10.57 [NESARC]). Odds ratios for each disorder remained statistically significant after matching on diagnostic status of dysthymia, major depressive disorder, alcohol abuse/dependence, substance abuse/dependence, bipolar disorder I, bipolar disorder II, all other anxiety disorders, and on sociodemographic variables. CONCLUSIONS: This is the first report to present evidence that each anxiety disorder is associated with suicide ideation and suicide attempts beyond the effects of co-occurring mental disorders. These findings warrant consideration in assessment, intervention, and related policies.

Severity of fall-based injuries, fear of falling, and activity restriction: sex differences in a population-based sample of older Canadian adults.

OBJECTIVES: Little is known about how different fall-based injuries relate to fear of falling and activity restriction, and if these relationships differ between sexes. We explored fear of falling and activity restriction in individuals who have experienced fall-based injuries. METHODS: A total of 16,369 older adults from the Canadian Community Health Survey reported their worst fall-based injury, whether they experience fear of falling, and whether they restrict activities from fear of falling. RESULTS: Females had greater odds of fear of falling than males. Only females who experienced a fracture or head injury had increased odds of fear of falling and only females who experienced a head injury had increased odds of restricting activities compared with females who fell without injury. DISCUSSION: Only severe fall-based injuries are associated with fear of falling and activity restriction, and this relationship is unique to females. Sex differences warrant further investigation and suggest a need for targeted interventions.

"What if I make a mistake?": intolerance of uncertainty is associated with poor behavioral performance.

Intolerance of uncertainty (IU) has been posited as ubiquitous across experiences of anxiety; however, studies testing how IU impacts behavior remain scant. The current study examined the impact of IU on performance during a keyboard typing task, a relatively complex and common behavior. A total of 40 members of the university community completed the task and measures of IU, trait anxiety, negative affect, and state anxiety. Heart rate and skin conductance were also assessed during the task as indices of state anxiety. IU was independently and substantially associated with slower typing speed (part r = -0.68) beyond other measured psychological and physiological variables but was not associated with typing errors. Prospective and inhibitory IU, as manifestations of IU, did not seemingly differ in their relationship with performance. IU may negatively impact day-to-day behaviors and contribute to undesired consequences. Further research is needed to explore whether this relationship warrants consideration in models of anxiety disorders.

Validation of the Yale-Brown Obsessive-Compulsive Severity Scale in African Americans with obsessive-compulsive disorder.

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is widely used in the assessment of obsessive-compulsive disorder (OCD), but the psychometric properties of the instrument have not been examined in African Americans with OCD. Therefore, the purpose of this study is to explore the properties of the Y-BOCS severity scale in this population. Participants were 75 African American adults with a lifetime diagnosis of OCD. They completed the Y-BOCS, the Beck Anxiety Inventory (BAI), the Beck Depression Inventory-II (BDI-II), and the Multigroup Ethnic Identity Measure (MEIM). Evaluators rated OCD severity using the Clinical Global Impression Scale (CGI) and their global assessment of functioning (GAF). The Y-BOCS was significantly correlated with both the CGI and GAF, indicating convergent validity. It also demonstrated good internal consistency (α=0.83) and divergent validity when compared to the BAI and BDI-II. Confirmatory factor analyses tested five previously reported models and supported a three-factor solution, although no model exhibited excellent fit. An exploratory factor analysis was conducted, supporting a three-factor solution. A linear regression was conducted, predicting CGI from the three factors of the Y-BOCS and the MEIM, and the model was significant. The Y-BOCS appears to be a valid measure for African American populations.

The center for epidemiologic studies depression scale: a review with a theoretical and empirical examination of item content and factor structure.

BACKGROUND: The Center for Epidemiologic Studies Depression Scale (CES-D; Radloff, 1977) is a commonly used freely available self-report measure of depressive symptoms. Despite its popularity, several recent investigations have called into question the robustness and suitability of the commonly used 4-factor 20-item CES-D model. The goal of the current study was to address these concerns by confirming the factorial validity of the CES-D. METHODS AND FINDINGS: Differential item functioning estimates were used to examine sex biases in item responses, and confirmatory factor analyses were used to assess prior CES-D factor structures and new models heeding current theoretical and empirical considerations. Data used for the analyses included undergraduate (n = 948; 74% women), community (n = 254; 71% women), rehabilitation (n = 522; 53% women), clinical (n =84; 77% women), and National Health and Nutrition Examination Survey (NHANES; n = 2814; 56% women) samples. Differential item functioning identified an item as inflating CES-D scores in women. Comprehensive comparison of the several models supported a novel, psychometrically robust, and unbiased 3-factor 14-item solution, with factors (i.e., negative affect, anhedonia, and somatic symptoms) that are more in line with current diagnostic criteria for depression. CONCLUSIONS: Researchers and practitioners may benefit from using the novel factor structure of the CES-D and from being cautious in interpreting results from the originally proposed scale. Comprehensive results, implications, and future research directions are discussed.

Pain-related anxiety influences pain perception differently in men and women: a quantitative sensory test across thermal pain modalities.

The sexes differ with respect to perception of experimental pain. Anxiety influences pain perception more in men than in women; however, there lacks research exploring which anxiety constructs influence pain perception differentially between men and women. Furthermore, research examining whether depression is associated with pain perception differently between the sexes remains scant. The present investigation was designed to examine how trait anxiety, pain-related anxiety constructs (ie, fear of pain, pain-related anxiety, anxiety sensitivity), and depression are associated with pain perception between the sexes. A total of 95 nonclinical participants (55% women) completed measures assessing the constructs of interest and participated in quantitative sensory testing using heat and cold stimuli administered by a Medoc Pathway Pain and Sensory Evaluation System. The findings suggest that pain-related anxiety constructs, but not trait anxiety, are associated with pain perception. Furthermore, these constructs are associated with pain intensity ratings in men and pain tolerance levels in women. This contrasts with previous research suggesting that anxiety influences pain perception mostly or uniquely in men. Depression was not systematically associated with pain perception in either sex. Systematic relationships were not identified that allow conclusions regarding how fear of pain, pain-related anxiety, and anxiety sensitivity may contribute to pain perception differentially in men and women; however, anxiety sensitivity was associated with increased pain tolerance, a novel finding needing further examination. The results provide directions for future research and clinical endeavors and support that fear and anxiety are important features associated with hyperalgesia in both men and women.

Fear of injury predicts self-reported and behavioral impairment in patients with chronic low back pain.

UNLABELLED: Fear of injury has been posited as crucial in pain-related anxiety and in the development of chronic pain; however, research has only measured fear of injury indirectly through other constructs (eg, fear of illness and fear of movement). The current study tested fear of injury as an independent contributor to pain-related anxiety and impairment. Patients (n = 78; 37% women) in a work-hardening treatment program for chronic low back pain completed self-report measures of pain-related anxiety, anxiety sensitivity, fear of injury, current pain, and impairment. Behavioral measures of impairment included lifting capacity, treatment outcomes, and days absent from treatment. Structural equation modeling tested the role of fear of injury within contemporary theory. Fit for the theoretical model was excellent and superior to an alternative model. Variance accounted for in pain-related anxiety by fear of injury, anxiety sensitivity, and current pain was 64%, while pain-related anxiety and current pain predicted 49% of variance in latent impairment. Fear of injury directly predicted pain-related anxiety (ß = .42) and indirectly predicted impairment through pain-related anxiety (ß = .19). Fear of injury may warrant theoretical and clinical consideration as an important contributor to pain-related anxiety and impairment; however, research is needed to explore how it may be causally related with other constructs. PERSPECTIVE: Fear of injury directly predicts pain-related anxiety and indirectly predicts self-reported and behavioral impairment. Fear of injury may warrant inclusion in contemporary theories of chronic pain. Clinicians may benefit from considering the construct in interventions for chronic pain.

Objective and perceived arousal during performance of tasks with elements of social threat: the influence of anxiety sensitivity.

BACKGROUND AND OBJECTIVES: Physiological arousal serves to maintain social anxiety disorder by skewing self-perception. Anxiety sensitivity is associated with the disorder and exaggerated perceptions of arousal, but has not been tested as explaining exaggerated perceived arousal in social contexts. The aim of this investigation was to address this issue. METHODS: A total of 42 individuals participated in three tasks associated with potential social threat (i.e., a speech, typing task, hyperventilation) and completed measures of trait social anxiety and anxiety sensitivity. State anxiety, perceived arousal, and objective arousal were assessed during each task. RESULTS: Trait social anxiety and anxiety sensitivity were correlated with state anxiety and perceived arousal, but not objective arousal, during the tasks. Anxiety sensitivity mediated the relationships between trait social anxiety and perceived arousal and between trait social anxiety and state anxiety for the typing and hyperventilation tasks. LIMITATIONS: Although the sample likely included a number of individuals with social anxiety disorder, the sample was mostly comprised of individuals without a diagnosis. The current results can be extended to clinical presentations to some extent, but future research is needed to further explore the demonstrated relationships in samples of individuals with social anxiety disorder. CONCLUSIONS: Anxiety sensitivity may play a crucial role in perceptions of arousal and state anxiety in the context of potential social threats, warranting attention from researchers and clinicians focussing on social anxiety disorder.

Increasingly certain about uncertainty: Intolerance of uncertainty across anxiety and depression.

Intolerance of uncertainty (IU) - a dispositional characteristic resulting from negative beliefs about uncertainty and its implications - may be an important construct in anxiety disorders and depression. Despite the potential importance of IU, clinical data on the construct remains relatively scant and focused on generalized anxiety disorder and obsessive-compulsive disorder. The present study systematically investigated IU, as measured by the Intolerance of Uncertainty Scale-12 (IUS-12), across groups diagnosed with anxiety disorders (i.e., social anxiety disorder, panic disorder, generalized anxiety disorder, obsessive-compulsive disorder) or depression (clinical sample: n=376; 61% women), as well as undergraduate (n=428; 76% women) and community samples (n=571; 67% women). Analysis of variance revealed only one statistically significant difference in IUS-12 scores across diagnostic groups in the clinical sample; specifically, people with social anxiety disorder reported higher scores (p<.01; η(2)=.03) than people with panic disorder. People diagnosed with an anxiety disorder or depression reported significantly and substantially higher IUS-12 scores relative to community and undergraduate samples. Furthermore, IUS-12 score distributions were similar across diagnostic groups as demonstrated by Kernel density estimations, with the exception of panic disorder, which may have a relatively flat distribution of IU. Response patterns were invariant across diagnostic groups as demonstrated by multi-group confirmatory factor analyses, but varied between clinical and nonclinical samples. Overall, the findings suggest IU may serve as an important transdiagnostic feature across anxiety disorders and depression. In addition, robust support was found for the proposed 2-factor model of the IUS-12. Comprehensive findings, implications, and future research directions are discussed.