Effects of glucocorticoid administration on the salience network and default mode network in patients with spider phobia (original) (raw)
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Glucocorticoid administration restores salience network activity in patients with spider phobia
Depression and anxiety, 2018
Glucocorticoids reduce phobic fear in patients with anxiety disorders. Although the neurobiology of anxiety disorders is not fully understood, convergent structural and functional neuroimaging studies have identified abnormalities in various brain regions, including those in the salience network (SN) and default mode network (DMN). Here, we examine the effects of glucocorticoid administration on SN and DMN activity during the processing of phobic stimuli. We use functional magnetic resonance imaging to record brain activity in 24 female patients with spider phobia who were administered either 20 mg of cortisol or placebo while viewing pictures of spiders. Fourteen healthy female participants were tested with the same task but without substance administration. Independent component analysis (ICA) performed during stimulus encoding identified the SN and DMN as exhibiting synchronized activation in diverse brain regions; thus, we examined the effects of cortisol on these networks. Furt...
Glucocorticoid Administration Improves Aberrant Fear-Processing Networks in Spider Phobia
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2016
Glucocorticoids reduce phobic fear in patients with anxiety disorders. Previous studies have shown that fear-related activation of the amygdala can be mediated through the visual cortical pathway, which includes the fusiform gyrus, or through other pathways. However, it is not clear which of the pathways that activate the amygdala is responsible for the pathophysiology of a specific phobia and how glucocorticoid treatment alleviates fear processing in these neural networks. We recorded the brain activity with functional magnetic resonance imaging in patients with spider phobia, who received either 20 mg of cortisol or a placebo while viewing pictures of spiders. We also tested healthy participants who did not receive any medication during the same task. We performed dynamic causal modelling (DCM), a connectivity analysis, to examine the effects of cortisol on the networks involved in processing fear and to examine if there was an association between these networks and the symptoms o...
Acta neurobiologiae experimentalis, 2015
Steroid hormones may act through a rapid mechanism that does not require an intracellular steroid receptor and its effects on gene expression. In this study we have analysed this so-called non-genomic effect of testosterone on social anxiety in rats of both sexes using androgen and oestrogen receptor blockers. Male rats were divided into four groups: SHAM-CTRL (a sham operated group treated with oil as vehicle, n=10), SHAM-TST (a sham operated group treated with testosterone at a dose of 1 mg/kg, n=10), GDX-CTRL (a castrated group treated with oil, n=10) and GDX-TST (a castrated group treated with testosterone at a dose of 1 mg/kg, n=10). Female rats were divided into two groups: OVX-CTRL (an ovariectomized group treated with oil, n=10) and OVX-TST (an ovariectomized group treated with testosterone, n=10). The intracellular androgen receptor was blocked with flutamide and both intracellular oestrogen receptors were blocked with tamoxifen (a selective oestrogen receptor modulator). R...
Translational Psychiatry
Individuals with a social anxiety disorder (SAD) show hypofunctioning of the hypothalamus–pituitary-gonadal (HPG) axis, which is linked to social fear and avoidance behavior. As testosterone administration has been shown to facilitate social-approach behavior in this population, it may enhance the effectiveness of exposure treatment. In this proof-of-concept study, we performed a randomized clinical assay in which 55 women diagnosed with SAD received two exposure therapy sessions. Session 1 was supplemented with either testosterone (0.50 mg) or placebo. Next, transfer effects of testosterone augmentation on within-session subjective fear responses and SAD symptom severity were assessed during a second, unenhanced exposure session (session 2) and at a 1-month follow-up, respectively. The participants having received testosterone showed a more reactive fear pattern, with higher peaks and steeper reductions in fear levels in session 2. Post-hoc exploration of moderating effects of endo...