Examining the latent structure of worry and generalized anxiety in a clinical sample

Generalized anxiety disorder (GAD) is characterized by “pathological” worry, suggesting that GAD worriers differ qualitatively from non-GAD worriers. However, results from taxometric studies of worry in undergraduate and community samples have been mixed and to date, no studies have utilized clinical samples. The current study examined the latent structure of worry and GAD symptoms in a diagnostically heterogeneous clinical sample. Indicators were selected from the Penn State Worry Questionnaire-Abbreviated (n = 1175) and the GAD-7 (n = 638) and submitted to three taxometric procedures: MAXCOV, MAMBAC, and L-Mode. Results from all three procedures suggested that both worry and generalized anxiety are best conceptualized as dimensional constructs. Findings also indicated that ongoing conceptualization, assessment, and treatment of worry and GAD may be hampered by the application of a categorical framework.     

Appraisal of activating thoughts in generalized anxiety disorder

Worrying may be an avoidance behaviour preventing the discomfort of imagining future threats. To study the link between phasic physiological activation and thought contents, we recruited 32 generalized anxiety disorder (GAD) patients and 31 controls and asked them to report whatever was in their mind just prior to whenever they were prompted. Half of 20 prompts were triggered by non-specific skin conductance fluctuations (activating thoughts). Controls judged activating thoughts as being less pleasant. GAD participants judged activating thoughts as more anxiety provoking, less relaxing and less controllable. Not the level of activation but the appraisal of activating thoughts in a catastrophic fashion differentiates GAD patients from controls.     

The latent structure of oppositional defiant disorder in children and adults

An understanding of the latent structure of oppositional defiant disorder (ODD) is essential for better developing causal models, improving diagnostic and assessment procedures, and enhancing treatments for the disorder. Although much research has focused on ODD—including recent studies informing the diagnostic criteria for DSM-5—research examining the latent structure of ODD is sparse, and no known study has specifically undertaken a taxometric analysis to address the issue of whether ODD is a categorical or dimensional construct. To address this gap, the authors conducted two separate studies using a set of taxometric analyses with data from the NICHD Study of Early Child Care and Youth Development (child study; n = 969) and with data from a large mixed sample of adults, which included participants reporting psychiatric difficulties as well as healthy controls (adult study; n = 600). The results of a variety of non-redundant analyses across both studies revealed a dimensional latent structure for ODD symptoms among both children and adults. These findings are consistent with previous studies that have examined latent structure of related constructs (e.g., aggression, antisocial behavior) as well as studies that have examined the dimensional versus categorical structure of ODD using methods other than taxometric analysis.     

The impact of psychological treatment on intolerance of uncertainty in generalized anxiety disorder: A systematic review and meta-analysis

Research has demonstrated a strong link between intolerance of uncertainty and generalized anxiety disorder (GAD). The current systematic review and meta-analysis aimed to evaluate how effective evidence-based psychological treatments are at reducing intolerance of uncertainty for adults with GAD. An extensive literature search identified 26 eligible studies, with a total of 1199 participants with GAD. Psychological treatments (k = 32 treatment groups) yielded large significant within-group effect size from pre- to post-treatment and pre-treatment to follow-up for intolerance of uncertainty (g = 0.88; g = 1.05), as well as related symptoms including worry (g = 1.32; g = 1.45), anxiety (g = 0.94; g = 1.04) and depression (g = 0.96; g = 1.00). Psychological treatment also yielded a large significant between-group effect on intolerance of uncertainty (g = 1.35). Subgroups analysis found that CBT that directly targeted intolerance of uncertainty (CBT-IU) throughout treatment was significantly more effective than general CBT at reducing intolerance of uncertainty (p < 0.01) and worry (p < 0.01) from pre- to post treatment, however, this result was not maintained at follow-up. Meta-regression analyses supported this finding as increases in the amount of time spent directly targeting intolerance of uncertainty, significantly increased the effect size for both intolerance of uncertainty (z = 2.01, p < 0.01) and worry (z = 2.23, p < 0.01). Overall, these findings indicate that psychological treatments are effective at reducing IU, and related symptom measures of GAD.     

Latent structure of intermittent explosive disorder in an epidemiological sample

Intermittent explosive disorder (IED) is characterized by distinct periods of impulsive aggression marked by assaultive acts or destruction of property. However, impulsive aggression is also a feature of other disorders, all of which are viewed in diagnostic nomenclature as qualitatively distinct from IED. This state of affairs is problematic for categorical models unless it is demonstrated empirically that IED-related impulsive aggression is qualitatively distinct from impulsive aggression observable in other axis I and II disorders. The current study addresses this question using taxometric methods to examine the latent structure of IED. Participants were respondents on the Collaborative Psychiatric Epidemiological Surveys, which obtained data on a range of disorders including intermittent explosive disorder (N = 20,013) and a range of psychological variables. Indicator variables used were drawn from the survey items and submitted to select taxometric methods (MAMBAC and MAXEIG) to determine the relative fits of a taxonic versus dimensional model. The results of taxometric analyses provided support for a taxonic, rather than dimensional, structure for IED symptoms in the epidemiological sample. Taxon group membership was associated with treatment seeking, family history of anger attacks, lower age of onset of anger attacks, and male biological sex, providing strong support for the validity of the IED taxon.     

Intolerance of uncertainty as a mediator of reductions in worry in a cognitive behavioral treatment program for generalized anxiety disorder

Growing evidence suggests that intolerance of uncertainty (IU) is a cognitive vulnerability that is a central feature across diverse anxiety disorders, including generalized anxiety disorder (GAD). Although cognitive behavioral therapy (CBT) has been shown to reduce IU, it remains to be established whether or not reductions in IU mediate reductions in worry. This study examined the process of change in IU and worry in a sample of 28 individuals with GAD who completed CBT. Changes in IU and worry, assessed bi-weekly during treatment, were analyzed using multilevel mediation models. Results revealed that change in IU mediated change in worry (ab = −0.20; 95% CI [−.35, −.09]), but change in worry did not mediate change in IU (ab = −0.16; 95% CI [−.06, .12]). Findings indicated that reductions in IU accounted for 59% of the reductions in worry observed over the course of treatment, suggesting that changes in IU are not simply concomitants of changes in worry. Findings support the idea that IU is a critical construct underlying GAD.     

Latent profile analyses of posttraumatic stress disorder,depression and generalized anxiety disorder symptoms in trauma-exposed soldiers

Posttraumatic stress disorder (PTSD) is comorbid with major depressive disorder (MDD; Kessler et al., 1995) and generalized anxiety disorder (GAD; Brown et al., 2001). We aimed to (1) assess discrete patterns of post-trauma PTSD-depression-GAD symptoms using latent profile analyses (LPAs), and (2) assess covariates (gender, income, education, age) in defining the best fitting class solution. The PTSD Checklist (assessing PTSD symptoms), GAD-7 scale (assessing GAD symptoms), and Patient Health Questionnaire-9 (assessing depression) were administered to 1266 trauma-exposed Ohio National Guard soldiers. Results indicated three discrete subgroups based on symptom patterns with mild (class 1), moderate (class 2) and severe (class 3) levels of symptomatology. Classes differed in symptom severity rather than symptom type. Income and education significantly predicted class 1 versus class 3 membership, and class 2 versus class 3. In conclusion, there is heterogeneity regarding severity of PTSD-depression-GAD symptomatology among trauma-exposed soldiers, with income and education predictive of class membership.     

Prefrontal-limbic connectivity during worry in older adults with generalized anxiety disorder

Objectives: Although generalized anxiety disorder (GAD) is one of the most prevalent anxiety disorders in older adults, very little is known about the neurobiology of worry, the hallmark symptom of GAD in adults over the age of 60. This study investigated the neurobiology and neural circuitry of worry in older GAD patients and controls.

Method: Twenty older GAD patients and 16 age-matched controls (mean age = 67.88) were compared on clinical measures and neural activity during worry using functional magnetic resonance imaging.

Results: As expected, worry elicited activation in frontal regions, amygdala, and insula within the GAD group, with a similar but less prominent frontal pattern was observed in controls. Effective connectivity analyses revealed a positive directional circuit in the GAD group extending from ventromedial through dorsolateral prefrontal cortices, converging on the amygdala. A less complex circuit was observed in controls with only dorsolateral prefrontal regions converging on the amygdala; however, a separate circuit passing through the orbitofrontal cortex converged on the insula.

Conclusion: Results elucidate a different neurobiology of pathological versus normal worry in later life. A limited resource model is implicated wherein worry in GAD competes for the same neural resources (e.g. prefrontal cortical areas) that are involved in the adaptive regulation of emotion through cognitive and behavioral strategies.     

万拉法新与阿普唑仑治疗广泛性焦虑临床对照研究

目的比较万拉法新与佳乐安定的抗焦虑效果和副作用。方法符合CCMD-3广泛性焦虑诊断标准的123例患者，随机分为研究组和对照组；用HAMA评定症状变化，用TESS评定副作用，疗程6周。结果治疗组显好率、有效率分别为76．9％、92．30％，对照组分别为72．41％、89．66％，两组总有效率接近。治疗组副反应恶心、头痛、口干、嗜睡等较多见。结论万拉法新治疗广泛性焦虑效果较好、副反应轻微。     

Reliability and validity of DSM-IV generalized anxiety disorder features

The reliability of generalized anxiety disorder (GAD) features has been shown to be moderate, based on research utilizing the Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV), a semi-structured diagnostic interview. This may be a function of the criteria for the diagnosis of GAD, which have undergone much revision since its first inclusion in the Diagnostic and Statistical Manual of Mental Disorders. The reliability and validity of disorder feature ratings were examined in a diverse sample of patients who presented for assessment and treatment of excessive worry, generalized anxiety, or tension at an anxiety specialty clinic and who met criteria for a principal diagnosis of GAD (N = 129). Internal consistency of the ratings of excessiveness of worry, uncontrollability of worry, and the associated symptom cluster was moderate to low and varied by disorder feature. Inter-rater reliability for all features of GAD and severity of the disorder varied between good and poor. Additional findings showed that the GAD features, as measured using the ADIS-IV module, have modest to strong convergent validity, varying by feature, and poor discriminant validity when tested against measures of social anxiety. Potential reasons for rater disagreement are discussed. Results are also considered in terms of how they may inform the evolving criteria for GAD in DSM-V.     

Testing a cognitive model of generalized anxiety disorder in the eating disorders

Generalized anxiety disorder (GAD) is one of the most common comorbid disorders found in individuals with eating disorders. Despite this, little is known of shared vulnerability factors between the two disorders. The aim of the present study was to examine the four main components of a cognitive model for GAD in the eating disorders. One hundred and sixty-two females took part. Three groups were formed comprising of 19 participants with an eating disorder and GAD, 70 with an eating disorder without GAD and 73 healthy controls. All completed self-report questionnaires that measured eating attitudes, levels of GAD, intolerance of uncertainty, positive beliefs about worry, negative problem orientation, and cognitive avoidance. Participants with an eating disorder and GAD scored the highest on all four components when compared to healthy individuals and on most components when compared to those with an eating disorder. Participants with an eating disorder without GAD scored higher on all components compared to healthy controls. Findings extend our understanding of shared vulnerability factors between the eating disorders and GAD.     

Cortical surface anatomy in pediatric patients with generalized anxiety disorder

BackgroundIt is established that pediatric patients with generalized anxiety disorder (GAD) exhibit functional abnormalities and altered gray matter volumes in neural structures that subserve emotional processing, yet there are no data regarding the surface anatomy of the cerebral cortex in youth with GAD.MethodsUsing an automated surface-based approach (FreeSurfer), cortical thickness was assessed node-by-node over the entire cerebral cortex in adolescents with GAD and no co-occurring major depressive disorder (n = 13) and healthy subjects (n = 19).ResultsCompared with healthy adolescents, youth with GAD exhibited increased cortical thickness in the right inferolateral and ventromedial prefrontal cortex (i.e., inferior frontal gyrus), the left inferior and middle temporal cortex as well as the right lateral occipital cortex. No relationships were observed between cortical thickness and the severity of anxiety symptoms in the significant regions that were identified in the vertex-wise analysis.ConclusionsThese findings suggest that, in adolescents with GAD, abnormalities in cortical thickness are present in an ensemble of regions responsible for fear learning, fear extinction, reflective functioning (e.g., mentalization), and regulation of the amygdala.     

Metacognitive therapy for generalized anxiety disorder: an open trial

Generalized anxiety disorder (GAD) responds only modestly to existing cognitive-behavioural treatments. This study investigated a new treatment based on an empirically supported metacognitive model [Wells, (1995). Metacognition and worry: A cognitive model of generalized anxiety disorder. Behavioural and Cognitive Psychotherapy, 23, 301-320; Wells, (1997). Cognitive therapy of anxiety disorders: A practice manual and conceptual guide. Chichester, UK: Wiley]. Ten consecutive patients fulfilling DSM-IV criteria for GAD were assessed before and after metacognitive therapy, and at 6, and 12-month follow-up. Patients were significantly improved at post-treatment, with large improvements in worry, anxiety, and depression (ESs ranging from 1.04-2.78). In all but one case these were lasting changes. Recovery rates were 87.5% at post treatment and 75% at 6 and 12 months. The treatment appears promising and controlled evaluation is clearly indicated.     

Making something out of nothing: neutral content modulates attention in generalized anxiety disorder

Background: Although an attentional bias for threat has been implicated in generalized anxiety disorder (GAD), evidence supporting such a bias has been inconsistent. This study examines whether exposure to different emotional content modulates attention disengagement and impairs the perception of subsequently presented nonemotional targets in GAD. Methods: Patients with GAD (n = 30) and controls (n = 30) searched for a target embedded within a series of rapidly presented images. Critically, an erotic, fear, disgust, or neutral distracter image appeared 200 msec or 800 msec before the target. Results: Impaired target detection was observed among GAD patients relative to controls following only fear and neutral distractors. However, this effect did not significantly vary as a function of distractor stimulus duration before the target. Furthermore, group differences in target detection after fear distractors were no longer significant when controlling target detection after neutral distractors. Subsequent analysis also revealed that the impaired target detection among those with GAD relative to controls following neutral (but not fear) distractors was mediated by deficits in attentional control. Conclusions: The implications of these findings for further delineating the function of attentional biases in GAD are discussed. Depression and Anxiety, 2011. © 2011 Wiley‐Liss, Inc.     

Reliability and validity of the dimensional features of generalized anxiety disorder

The reliability and validity of the dimensional features of generalized anxiety disorder (GAD) were examined in a diverse sample of 508 outpatients with anxiety and mood disorders who underwent two independent administrations of the Anxiety Disorders Interview Schedule for DSM-IV: Lifetime version (ADIS-IV-L; Di Nardo, Brown, & Barlow, 1994). Inter-rater reliability was higher in the full sample than in patients with current GAD. Additionally, the presence of a mood disorder weakened inter-rater reliability. We also explored the unique contribution of excessiveness and uncontrollability of worry to various clinical outcomes and found that excessiveness predicted anxiety, depression, and stress self-report measures, and uncontrollability predicted clinical severity and number of diagnoses. Findings are discussed with regard to their implications for the classification of GAD (e.g., utility of dimension-based assessment to improve the classification of psychological disorders).     

Screening for generalized anxiety disorder using the Penn State Worry Questionnaire: a receiver operating characteristic analysis

The present study examined the usefulness of the Penn State Worry Questionnaire (PSWQ) as a means of screening for generalized anxiety disorder (GAD). Using receiver operating characteristic analyses, the accuracy of the PSWQ in screening for GAD was examined in both clinical and analogue diagnosed GAD samples. Given high comorbidity between GAD and other emotional disorders, we also investigated the usefulness of the PSWQ in selecting non-cases of GAD that were also free of PTSD, social phobia, or depression versus non-cases of GAD that met criteria for one of these conditions. The overall usefulness of the PSWQ as a screening device is discussed.     

Preliminary support for gender differences in response to fluoxetine for generalized anxiety disorder

Women have a higher prevalence of generalized anxiety disorder (GAD) than do men, but few studies have assessed gender differences in response to pharmacotherapy. In this study we examined gender as a correlate of response to 6 weeks of open, prospective fluoxetine treatment in 23 men and 22 women with a primary diagnosis of GAD. There was no difference by gender in age or prevalence of mood and anxiety comorbidity; however, GAD onset occurred at a significantly younger age in women compared with men. Despite a lack of difference in baseline severity measures, women had a significantly poorer response to fluoxetine as measured by both the Hamilton Anxiety Rating Scale (HAM-A) and Clinician Global Impression-Severity Scale (CGI-S). In multivariate analyses, there was a significant interaction between age of onset and gender: men with younger age of onset and women with older age of onset exhibited poorer response on the HAM-A. These data, though limited in sample size and by the post hoc nature of our analyses, offer preliminary support that women with GAD, particularly those with a later age of onset, may have a poorer response to the selective serotonin reuptake inhibitor (SSRI) fluoxetine. Larger placebo-controlled trials are needed to more definitively examine gender and treatment response in anxiety disorders.     

An experience sampling investigation of emotion and worry in people with generalized anxiety disorder

Emotion-oriented theories (e.g., emotion dysregulation model, Mennin et al., 2005; contrast avoidance model; Newman & Llera, 2011) posit that people with Generalized Anxiety Disorder (GAD) have disturbances in emotion, experience negative emotion as aversive and in turn use maladaptive strategies, including worry, to regulate their distress. Much of what is known about emotion in the context of GAD is based on studies employing static methodologies. It is proposed that constructs and methodologies from the literature on emotion dynamics offer a complementary perspective. The principal aims of the study were to identify an emotion profile for people with GAD and to examine the direct effect of worry on subsequent negative and positive emotions via the experience sampling method. Participants included people with GAD (GAD group; n = 39) and people without GAD (nonclinical control [NCC] group; n = 41). Relative to the NCC group, the GAD group exhibited an emotion profile characterized by elevated mean intensity, greater instability and greater inertia of negative emotions and lower mean intensity, greater instability of positive emotions, but did not differ on inertia of positive emotions. People with GAD were found to have greater worry inertia and worry was also found to be associated with a subsequent increase in negative emotion, and this was more pronounced for the GAD group relative to the NCC group. The findings inform emotion-oriented models, provide unique insights into the dynamic emotional experiences of those with GAD and reinforce the benefits of the experience sampling methodology to study GAD-relevant processes.     

Salivary cortisol is associated with diagnosis and severity of late-life generalized anxiety disorder

Age-associated alterations in hypothalamic-pituitary-adrenal (HPA) axis functioning may make individuals more susceptible to HPA dysregulation in the context of mood and anxiety disorders. Little to no research has been done to examine HPA axis function in generalized anxiety disorder (GAD), particularly in late-life GAD, the most prevalent anxiety disorder in the elderly. The study sample consisted of 71 GAD subjects and 40 nonanxious comparison subjects over 60 years of age. We examined the hypotheses that elderly individuals with GAD will have elevated salivary cortisol levels compared to nonanxious subjects, and that elevated cortisol levels in GAD will be associated with measures of symptom severity. We report that late-life GAD is characterized by elevated basal salivary cortisol levels, with higher peak cortisol levels and larger areas under the curve, compared to nonanxious subjects. Additionally, severity of GAD as measured by the GAD Severity Scale and the Penn State Worry Questionnaire are positively correlated with cortisol levels. These data demonstrate HPA axis dysfunction in late-life GAD and suggest the need for additional research on the influence of aging on HPA axis function in mood and anxiety disorders.