78 research outputs found

    Arousal modulation of memory and amygdala‐parahippocampal connectivity: A PET‐psychophysiology study in specific phobia

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    Phobic fear is accompanied by intense bodily responses modulated by the amygdala. An amygdala moderated psychophysiological measure related to arousal is electrodermal activity. We evaluated the contributions of electrodermal activity to amygdala‐parahippocampal regional cerebral blood flow (rCBF) during phobic memory encoding in subjects with spider or snake phobia. Recognition memory was increased for phobia‐related slides and covaried with rCBF in the amygdala and the parahippocampal gyrus. The covariation between parahippocampal rCBF and recognition was related to electrodermal activity suggesting that parahippocampal memory processes were associated with sympathetic activity. Electrodermal activity further mediated the amygdala effect on parahippocampal activity. Memory encoding during phobic fear therefore seems contingent on amygdala's influence on arousal and parahippocampal activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86974/1/j.1469-8986.2011.01231.x.pd

    Therapygenetic effects of 5-HTTLPR on cognitive-behavioral therapy in anxiety disorders: a meta-analysis

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    There is a recurring debate on the role of the serotonin transporter gene linked polymorphic region (5-HTTLPR) in the moderation of response to cognitive behavioral therapy (CBT) in anxiety disorders. Results, however, are still inconclusive. We here aim to perform a meta-analysis on the role of 5-HTTLPR in the moderation of CBT outcome in anxiety disorders. We investigated both categorical (symptom reduction of at least 50%) and dimensional outcomes from baseline to post-treatment and follow-up. Original data were obtained from ten independent samples (including three unpublished samples) with a total of 2,195 patients with primary anxiety disorder. No significant effects of 5-HTTLPR genotype on categorical or dimensional outcomes at post and follow-up were detected. We conclude that current evidence does not support the hypothesis of 5-HTTLPR as a moderator of treatment outcome for CBT in anxiety disorders. Future research should address whether other factors such as long-term changes or epigenetic processes may explain further variance in these complex gene-environment interactions and molecular-genetic pathways that may confer behavioral change following psychotherapy

    ENIGMA-anxiety working group : Rationale for and organization of large-scale neuroimaging studies of anxiety disorders

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    Altres ajuts: Anxiety Disorders Research Network European College of Neuropsychopharmacology; Claude Leon Postdoctoral Fellowship; Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, 44541416-TRR58); EU7th Frame Work Marie Curie Actions International Staff Exchange Scheme grant 'European and South African Research Network in Anxiety Disorders' (EUSARNAD); Geestkracht programme of the Netherlands Organization for Health Research and Development (ZonMw, 10-000-1002); Intramural Research Training Award (IRTA) program within the National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, MH002781); National Institute of Mental Health under the Intramural Research Program (NIMH-IRP, ZIA-MH-002782); SA Medical Research Council; U.S. National Institutes of Health grants (P01 AG026572, P01 AG055367, P41 EB015922, R01 AG060610, R56 AG058854, RF1 AG051710, U54 EB020403).Anxiety disorders are highly prevalent and disabling but seem particularly tractable to investigation with translational neuroscience methodologies. Neuroimaging has informed our understanding of the neurobiology of anxiety disorders, but research has been limited by small sample sizes and low statistical power, as well as heterogenous imaging methodology. The ENIGMA-Anxiety Working Group has brought together researchers from around the world, in a harmonized and coordinated effort to address these challenges and generate more robust and reproducible findings. This paper elaborates on the concepts and methods informing the work of the working group to date, and describes the initial approach of the four subgroups studying generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobia. At present, the ENIGMA-Anxiety database contains information about more than 100 unique samples, from 16 countries and 59 institutes. Future directions include examining additional imaging modalities, integrating imaging and genetic data, and collaborating with other ENIGMA working groups. The ENIGMA consortium creates synergy at the intersection of global mental health and clinical neuroscience, and the ENIGMA-Anxiety Working Group extends the promise of this approach to neuroimaging research on anxiety disorders

    Social Phobia. From Epidemiology to Brain Function

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    Social phobia is a disabling anxiety disorder characterized by an excessive fear of negative evaluation in social situations. The present thesis explored the epidemiology and neurobiology of the disorder. By means of a mailed questionnaire, the point prevalence of social phobia in the Swedish general population was estimated at 15.6%. However, prevalence rates varied between 1.9 and 20.4% across the different levels of distress and impairment used to define cases. Thus, although social anxiety is widespread within the community, the precise diagnostic boundaries for social phobia are difficult to determine. Social phobia was associated with female gender, low educational attainment, psychoactive medication use, and lack of social support. A cluster analysis revealed that subtypes of social phobia mainly differed dimensionally on a mild-moderate-severe continuum, with number of cases declining with increasing severity. Public speaking was the most common social fear in all groups of social phobics and in the population at large. In the neurobiological studies, positron emission tomography was used to examine brain serotonin metabolism and changes in the regional cerebral blood flow (rCBF) response to public speaking stress following treatment with a selective serotonin reuptake inhibitor (SSRI) or cognitive-behavioral group therapy. Social phobics exhibited lowered serotonin turnover, relative to non-phobics, mainly in the medial temporal cortex including the bilateral rhinal and periamygdaloid regions. Symptom improvement with cognitive-behavioral- as well as SSRI-treatment was accompanied by a reduced rCBF-response to public speaking in the amygdala, hippocampus and adjacent temporal cortex, i.e. regions that serve important functions in anxiety. Thorough suppression of rCBF in limbic brain regions was associated with favorable long-term treatment outcome. These results provide neuroimaging evidence for a presynaptic serotonergic dysfunction in social phobia and for a common neural mechanism whereby psychological and pharmacological anti-anxiety treatments act

    Imaging the cerebellum in post-traumatic stress and anxiety disorders : a mini-review

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    Post-traumatic stress disorder (PTSD) and anxiety disorders are among the most prevalent psychiatric conditions worldwide sharing many clinical manifestations and, most likely, neural mechanisms as suggested by neuroimaging research. While the so-called fear circuitry and traditional limbic structures of the brain, particularly the amygdala, have been extensively studied in sufferers of these disorders, the cerebellum has been relatively underexplored. The aim of this paper was to present a mini-review of functional (task-activity or resting-state connectivity) and structural (gray matter volume) results on the cerebellum as reported in magnetic resonance imaging studies of patients with PTSD or anxiety disorders (49 selected studies in 1,494 patients). While mixed results were noted overall, e.g., regarding the direction of effects and anatomical localization, cerebellar structures like the vermis seem to be highly involved. Still, the neurofunctional and structural alterations reported for the cerebellum in excessive anxiety and trauma are complex, and in need of further evaluation

    Descriptive characteristics.

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    <p>Descriptive characteristics.</p

    Immediate results with time x group interaction and estimated means and standard error at pre and post (n = 204) in accordance with the Intention-to-treat principle.

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    <p>In addition, to facilitate the understanding the observed standard deviation was added (n = 204 and 195 at pre and post respectively).</p><p>Note: ** = p<.01; *** = p<.001.</p
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