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Background Obsessive compulsive disorder (OCD) is associated with elevated suicide risk, but the directionality of the association between OCD severity and suicidal ideation has not been established, which was the goal of this study. Methods Participants (n = 325) were adults with either a current or past diagnosis of Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) OCD who were assessed annually for suicidal ideation and OCD symptom severity for six years. Cross-lagged panel analyses statistically compared unidirectional and bidirectional models over time. Serious suicide-related adverse events were reported. Results The best-fitting and most parsimonious model included paths predicting suicidal ideation from OCD symptom severity, but not vice versa. These results were confirmed by comparing a model with cross-lagged paths constrained equal to a freely estimated model. Higher OCD symptom severity in a given year was associated with a higher suicidal ideation severity in the subsequent year. Five suicide-related adverse events were reported throughout the duration of the study, including two suicide deaths and three suicide attempts. Limitations The study relied on a single-item, annual measure of suicidal ideation in adults, with substantial variability in severity of suicide risk, and missing data increased with later observations in the study. Discussion OCD symptom severity predicted next year suicidal ideation severity. In contrast, suicidal ideation severity in a given year did not predict next-year OCD symptom severity in this OCD sample. Thus, rather than waiting for suicidal ideation to resolve, clinicians should consider providing empirically supported treatments for OCD.

Social anxiety disorder (SAD) is characterized by exaggerated reactivity to social threat, often documented by biased attention to threatening information, and increased activation in brain regions involved in salience/threat processing. Attention training has been developed to ameliorate the attention bias documented in individuals with SAD, with mixed results. We investigated patterns of brain activation underlying acute attention modulation in 41 participants (29 with SAD and 12 health controls). We then investigated how brain activation changed over time in both groups in response to a 4-session attention training protocol (toward threat, away from threat, no-training control). Results revealed diminished pre-training deactivation in the insula in SAD participants during attention modulation. SAD participants also demonstrated an increase in insula deactivation over time, suggestive of an improvement in attention modulation of emotion, and this was associated with a decrease in symptom severity. Attention training did not, itself, lead to clinical improvement, though there was a trend level effect of training toward threat on increased insula deactivation over time. While deficits in attentional control and emotion modulation are documented in individuals with SAD, current attention training protocols are not robustly effective in ameliorating aberrant functioning. Pursuit of training protocols that have more robust impacts on the relevant neural circuitry may have some value.

Background: Individuals with panic disorder (PD) exhibit a hypersensitivity to inhaled carbon dioxide, possibly reflecting a lowered threshold for sensing signals of suffocation. Animal studies have shown that carbon dioxide–mediated fear behavior depends on chemosensing of acidosis in the amygdala via the acid-sensing ion channel ASIC1a. We examined whether the human ortholog of the ASIC1a gene, ACCN2, is associated with the presence of PD and with amygdala structure and function. Methods: We conducted a case-control analysis (n ¼ 414 PD cases and 846 healthy controls) of ACCN2 single nucleotide polymorphisms and PD. We then tested whether variants showing significant association with PD are also associated with amygdala volume (n ¼ 1048) or task-evoked reactivity to emotional stimuli (n ¼ 103) in healthy individuals. Results: Two single nucleotide polymorphisms at the ACCN2 locus showed evidence of association with PD: rs685012 (odds ratio ¼ 1.32, gene-wise corrected p ¼ .011) and rs10875995 (odds ratio ¼ 1.26, gene-wise corrected p ¼ .046). The association appeared to be stronger when early-onset (age # 20 years) PD cases and when PD cases with prominent respiratory symptoms were compared with controls. The PD risk allele at rs10875995 was associated with increased amygdala volume (p ¼ .035) as well as task-evoked amygdala reactivity to fearful and angry faces (p ¼ .0048). Conclusions: Genetic variation at ACCN2 appears to be associated with PD and with amygdala phenotypes that have been linked to proneness to anxiety. These results support the possibility that modulation of acid-sensing ion channels may have therapeutic potential for PD.

Prior work has revealed that posttraumatic stress disorder (PTSD) is associated with altered (a) attentional performance and (b) resting-state functional connectivity (rsFC) in brain networks linked to attention. Here, we sought to characterize and link these behavioral and brain-based alterations in the context of Posner and Peterson's tripartite model of attention. Male military veterans with PTSD (N = 49; all deployed to Iraq or Afghanistan) and healthy age-and-gender-matched community controls (N = 26) completed the Attention Network Task. A subset of these individuals (36 PTSD and 21 controls) also underwent functional magnetic resonance imaging (fMRI) to assess rsFC. The behavioral measures revealed that the PTSD group was impaired at disengaging spatial attention, relative to the control group. FMRI measures further revealed that, relative to the control group, the PTSD group exhibited greater rsFC between the salience network and (a) the default mode network, (b) the dorsal attention network, and (c) the ventral attention network. Moreover, problems with disengaging spatial attention increased the rsFC between the networks above in the control group, but not in the PTSD group. The present findings link PTSD to both altered orienting of spatial attention and altered relationships between spatial orienting and functional connectivity involving the salience network. Interventions that target orienting and disengaging spatial attention may be a new avenue for PTSD research.

Anxiety disorders are among the most common psychiatric disorders, affecting one in four individuals over a lifetime. Although our understanding of the etiology of these disorders is incomplete, familial and genetic factors are established risk factors. However, identifying the specific casual genes has been difficult. Within the past several years, advances in molecular and statistical genetic methods have made the genetic dissection of complex disorders a feasible project. Here we provide an overview of these developments, with a focus on their implications for genetic studies of anxiety disorders. Although the genetic and phenotypic complexity of the anxiety disorders present formidable challenges, advances in neuroimaging and experimental animal models of anxiety and fear offer important opportunities for discovery. Real progress in identifying the genetic basis of anxiety disorders will require integrative approaches that make use of these biologic tools as well as larger-scale genomic studies. If successful, such efforts may yield novel and more effective approaches for the prevention and treatment of these common and costly disorders. Depression and Anxiety, 2009. © 2009 Wiley-Liss, Inc.