Transcript Neuroscience of GAD 2014/19/11

Neuroscience of GAD
Amin Asadollahpour Kargar
PhD Candidate of Cognitive Neuroscience
Manager of CYBER Psychology and Neurofeedback Center
CYBER Psychology and Neurofeedback Center
Tabriz, Iran
2014/19/11
[email protected]
www.CyberNeuro.com
What is Generalized Anxiety Disorder(GAD)?
DSM Criteria…
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Excessive anxiety and worry about a number of events or activities
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difficulty to control the worry
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associated with three (or more) of the following six symptoms
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Restlessness or feeling keyed up or on edge
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Being easily fatigued
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Difficulty concentrating
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Irritability
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Muscle tension
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Sleep disturbance (difficulty falling or staying asleep, or restless unsatisfying sleep)
What is GAD?
Key note for GAD is …
Worry!
and it is very difficult to control the worry!
What is GAD?
Behavioral Approach…
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Based on Behavioral approach to anxiety, every anxiety disorder must (and
must) contain a kind of …
Avoidance!
Repeated Avoidance is the keynote for feelings of anxiety…
… to become an Anxiety Disorder.
What is avoidance technique of a GAD
person?

Remember the key note of GAD! It is exactly the…
Worry!
Propositional sentences like “it will be disaster” produce worry which it avoids …??
What is it a GAD person avoids?
Images
Theory of Borkovec (1994)
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Worry is principally a verbal or semantic activity that serves to prevent the
full experience of anxiety.
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Worry prevents processing of negative emotions and all of their stimulus,
response, and meaning propositions (Barlow, 2004).
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Worry is associated with less imagery in GAD individuals
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Worry without accompanying images(Barlow and Durand,2014)
Role of Electroencephalography(EEG) in
theory of Borkovec…
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Borkovec(1986) discovered that worry led to increased EEG beta activity in
the frontal lobes, especially in the left frontal lobe.
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This means that there is much of language processing during worry in GAD
individuals.
Neuroscientific approach to GAD
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Neuroscientific approach to anything means that you have techniques and
tools which they let you gather your data directly from brain or body of
subject without his/her consciousness or decisions.
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Here we discuss four tools and technologies about GAD:
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Quantitative Electroencephalography (QEEG)
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Low Resolution Brain Electromagnetic Tomography (LORETA)
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Magnetic Resonance Imaging (MRI)
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functional Magnetic Resonance Imaging (fMRI)
QEEG Findings
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Comparing 41 GAD patients to healthy group, Saletu and his colleagues(2005)
found that there is increasing of
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Absolute Delta(1-4 Hz) in Prefrontal and Occipital
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Absolute Theta(4-8Hz) in Prefrontal and Cz
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Absolute Alpha1(8-10Hz) in left hemisphere and both Occipitals
Maps on EEG differences between 9 mental disorder patients and normal controls. Statistical probability maps (SPM) depicting
intergroup differences in total, absolute and relative power as well as the centroids of the delta, theta, alpha and beta frequency
bands (from top to bottom) are shown (birds eye view, nose at the top, left ear left, right ear right, whiie dots indicate electrode
positions). Orange, red and purple colors represent significant (p < 0.10,0.05 and 0.01, respecbvely) increases; dark green, light
blue and dark Mue indicate significant (p < 0.10,0.05 and 0.01, respectively) decreases, as compared with normal controls.
In columns from left to right, schizophrenics with a predominantly positive symptomatology (N: 18), for instance, exhibit an
attenuated absolute delta and theta power, while schizophrenics a predominantly negative symptomatology (N: 30) show an
increase. Major depression (N: So), generalized anxiety disorder (N: 41), agoraphobia (N: 21), obsessivecompulsive disorder
(N: 12), multi-infarct dementia (N: 24), senile dementia of the Alzheimer type (N: 24) and alcoholdependent patients currently
abstinent (N: 29) show different EEG maps, as compared with normal controls.
LORETA Findings

Comparing 44 GAD patients to matched normal controls, LORETA shows there
is significant increase in Alpha1 (8-10 Hz) in two brain regions: BA8 and
BA18(Saleto et.al, 2005).
Saleto et.al (2005)
Left:BA8 (Superior Frontal Gyrus)
Right:BA18 (Cuneus, Occipital Lobe)
Images made by giving LORETA X,Y and Z to BrainVoyager program
MRI Findings
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Comparing to healthy control group, GAD patients showed increase in
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Left and right Amygdala volume (De Bellis et.al, 2000, Hilbert et.al, 2014)
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Cortical thickness in right inferolateral and ventromedial prefrontal cortex
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Cortical thickness in left inferior and middle temporal cortex
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Cortical thickness in right lateral occipital cortex (Strawn et.al, 2014)
Brain regions with functional and structural
abnormalities implicated in GAD. Photo courtesy A.
Schienle (Schienle et.al, 2011)
fMRI Findings
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Comparing 26 GAD patients with 26 healthy control group, and using pictures
of neutral vs angry faces, GAD group showed (Holzel et.al, 2013):
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Increased activity in Amygdala and prefrontal cortex in response to neutral faces!
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There is no difference between groups in brain activity in response to angry faces!
Yassa et.al (2012)published a research titled “Functional MRI of the
amygdala and bed nucleus of the stria terminalis during conditions of
uncertainty in generalized anxiety disorder”
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They found that GAD patients, compared to controls, demonstrated
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decreased activity in the amygdala
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and increased activity in the BNST
Group contrast of Controls minus GAD patients shown at an uncorrected P value of .05 with
a 10-voxel cluster threshold. Increasesing activity in controls compared to GAD patients are
shown in red (bilateral amygdala) while decreases are shown in blue (Yassa et.al, 2012)
Thank you for your attention
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