fMRI reveals amygdala activation to human faces in social phobics

Abstract

Functional magnetic resonance imaging was used to determine the activation of the amygdala while seven social phobics and five healthy controls were exposed to slides of neutral faces as well as aversive odor stimuli. The amygdala was selectively activated in the social phobics during presentation of the face stimuli. The data show for the first time that the amygdala is active in human phobics when they are exposed to potentially fear-relevant stimuli. Further research is needed to determine the extent to which overactivation of the amygdala precedes or is a consequence of phobia.

Effects of Cannabidiol (CBD) on Regional Cerebral Blood Flow

“…Functional and structural changes in the amygdala have also been reported in PTSD (Pitman et al, 2001;Rauch et al, 1996;Shin et al, 1997;Rauch et al, 2000;Liberzon et al, 1999), panic disorder (Uchida et al, 2003;Bystritsky et al, 2001), generalized anxiety disorder (Thomas et al, 2001;De Bellis et al, 2000), and in social (Birbaumer et al, 1998;Tillfors et al, 2001;Furmark et al, 2002) and simple phobias . The reduction in amygdala activity that we observed with CBD is thus consistent with the anxiolytic effect that it had in our subjects.…”

A pilot study of amygdala volumes in pediatric generalized anxiety disorder

“…Alternatively, the increase in amygdala volume might be the result of increased anticipatory anxiety during development; however, rather than finding an increase or decrease in relevant brain structures, perturbations of the neural networks involved in anxiety symptoms from the healthy state compared to the diseased state is what is most critical in understanding the neurobiology of GAD. For example, results from recent functional MRI investigations of adults who suffer from social phobia revealed that the amygdala may be selectively activated during exposure to neutral faces (Birbaumer et al 1998) and show differing patterns of activation during conditioned aversive stimuli compared to healthy adults (Schneider et al 1999). The etiology, neuropsychological function, and the permanence of our anatomical findings in pediatric GAD need to be examined.…”

A Functional Magnetic Resonance Imaging Predictor of Treatment Response to Venlafaxine in Generalized Anxiety Disorder

“…Of specific relevance to the present experiment are data showing that greater rostral ACC (rACC) reactivity in response to facial expressions of emotion is correlated with lesser amygdala reactivity (6,7). Thus, facial expressions represent simple stimuli for assessing amygdalaprefrontal reactivity and provide a basis to assess amygdalaprefrontal function in psychopathology (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23).…”