The latent structure of social anxiety disorder and the performance only specifier: a taxometric analysis.

Social anxiety disorder (SAD) is often treated as a discrete diagnostic entity that represents a naturally occurring class, though empirical evidence largely supports a dimensional conceptualization of social fears. Further, the inclusion of a "performance only" specifier in the DSM-5 implies that individuals who experience intense social anxiety exclusively in performance situations are distinct from those with broader social fears. The purpose of the present research was to examine the latent structure of SAD and the DSM-5 "performance only" specifier in a large nonclinical sample (n = 2019). Three taxometric procedures (MAXCOV, MAMBAC, and L-Mode) were applied to indicators derived from two commonly used measures of social anxiety. Results yielded convergent evidence indicating that social anxiety exhibits a dimensional latent structure. Further, social performance anxiety demonstrates continuous relationships with milder social fears, suggesting that the "performance only" specifier may not represent a discrete entity. The implications of these findings for the assessment, diagnosis, classification, and treatment of social anxiety are discussed.

Cerebrocerebellar hypometabolism associated with repetitive blast exposure mild traumatic brain injury in 12 Iraq war Veterans with persistent post-concussive symptoms.

Disagreement exists regarding the extent to which persistent post-concussive symptoms (PCS) reported by Iraq combat Veterans with repeated episodes of mild traumatic brain injury (mTBI) from explosive blasts represent structural or functional brain damage or an epiphenomenon of comorbid depression or posttraumatic stress disorder (PTSD). Objective assessment of brain function in this population may clarify the issue. To this end, twelve Iraq war Veterans (32.0 ± 8.5 [mean ± standard deviation (SD)] years of age) reporting one or more blast exposures meeting American Congress of Rehabilitation Medicine criteria for mTBI and persistent PCS and 12 cognitively normal community volunteers (53.0 ± 4.6 years of age) without history of head trauma underwent brain fluorodeoxyglucose positron emission tomography (FDG-PET) and neuropsychological assessments and completed PCS and psychiatric symptom rating scales. Compared to controls, Veterans with mTBI (with or without PTSD) exhibited decreased cerebral metabolic rate of glucose in the cerebellum, vermis, pons, and medial temporal lobe. They also exhibited subtle impairments in verbal fluency, cognitive processing speed, attention, and working memory, similar to those reported in the literature for patients with cerebellar lesions. These FDG-PET imaging findings suggest that regional brain hypometabolism may constitute a neurobiological substrate for chronic PCS in Iraq combat Veterans with repetitive blast-trauma mTBI. Given the potential public health implications of these findings, further investigation of brain function in these Veterans appears warranted.

The Circumscribed Fear Measure: Development and initial validation of a trans-stimulus phobia measure.

Extant stimulus-specific fear measures are limited to a small number of stimuli and contain significantly different content. This article describes 2 studies that develop a more flexible fear measure­the Circumscribed Fear Measure (CFM)­and examine its psychometric properties. In Study 1, participants (N = 771) completed an initial item pool while considering their most feared stimulus. Results of factor analyses were used to propose a 25-item, 5-factor measure that would span the domain of specific phobia reactions, applicable to different stimuli. In Study 2, participants (N = 959) completed the 25-item CFM, extant phobia measures, and a measure of disability. The CFM exhibited a 5-scale structure that had an equivalent structure across different stimuli. It showed good factorial validity, reliability, and generally good convergent and discriminant validity. Criterion validity was commensurate with that of extant phobia measures. The use of the measure as an index of an individual's greatest fear is also discussed. The CFM shows promise and could have substantial research and clinical utility.

Self-Focused Attention and Post-Event Processing: Relevance to Social Performance Anxiety and Social Interaction Anxiety.

This study examined the roles of self-focused attention and post-event processing in social performance anxiety and social interaction anxiety. College students (N = 101) completed measures of social performance anxiety, social interaction anxiety, self-focused attention, post-event processing, and beliefs related to social anxiety. Interoceptive self-focused attention and post-event processing predicted social performance anxiety after controlling for social interaction anxiety. The associations with social interaction anxiety were not significant after controlling for social performance anxiety. Associations of behavioral self-focused attention with social performance anxiety and social interaction anxiety were not significant after controlling for interoceptive self-focused attention. No evidence of an interaction between self-focused attention and post-event processing in the prediction of social anxiety was found. This study found no evidence that the associations of interoceptive self-focused attention and post-event processing with social performance anxiety were statistically mediated by high standards, conditional beliefs about self, and unconditional beliefs about self. These results and their theoretical implications are discussed.