Differential alterations of resting‐state functional connectivity in generalized anxiety disorder and panic disorder

Summary & key facts

Researchers used resting-state brain scans to compare whole-brain functional connections in 21 people with generalized anxiety disorder (GAD), 18 people with panic disorder (PD), and 22 matched controls. They used a new 'scaled correlation' measure of connectivity. GAD showed stronger connections between the hippocampus/parahippocampus and the fusiform gyrus. PD showed stronger connections between the somatosensory cortex and the thalamus. Each disorder's connectivity changes lined up with how severe patients' symptoms were. The authors say the GAD pattern may relate to fear generalization, while the PD pattern may relate to sensing internal body signals (interoception). The study is based o

Key facts:

• The study compared 21 people with generalized anxiety disorder (GAD), 18 people with panic disorder (PD), and 22 matched control subjects.
• Researchers used resting-state fMRI and a whole-brain metric called 'scaled correlation' to measure functional connectivity.
• People with GAD showed increased functional connectivity between the hippocampus/parahippocampus and the fusiform gyrus.
• People with PD showed increased functional connectivity between the somatosensory cortex and the thalamus.
• In each disorder, the disrupted connectivity patterns correlated with how severe patients' symptoms were.
• The authors interpret the GAD connectivity change as linked to fear generalization and the PD change as linked to interoceptive processing, but the study is observational and does not prove causation.

Abstract

Generalized anxiety disorder (GAD) and panic disorder (PD) are most common anxiety disorders with high lifetime prevalence while the pathophysiology and disease-specific alterations still remain largely unclear. Few studies have taken a whole-brain perspective in the functional connectivity (FC) analysis of these two disorders in resting state. It limits the ability to identify regionally and psychopathologically specific network abnormalities with their subsequent use as diagnostic marker and novel treatment strategy. The whole brain FC using a novel FC metric was compared, that is, scaled correlation, which they demonstrated to be a reliable FC statistics, but have higher statistical power in two-sample t-test of whole brain FC analysis. About 21 GAD and 18 PD patients were compared with 22 matched control subjects during resting-state, respectively. It was found that GAD patients demonstrated increased FC between hippocampus/parahippocampus and fusiform gyrus among the most significantly changed FC, while PD was mainly associated with greater FC between somatosensory cortex and thalamus. Besides such regional specificity, it was observed that psychopathological specificity in that the disrupted FC pattern in PD and GAD correlated with their respective symptom severity. The findings suggested that the increased FC between hippocampus/parahippocampus and fusiform gyrus in GAD were mainly associated with a fear generalization related neural circuit, while the greater FC between somatosensory cortex and thalamus in PD were more likely linked to interoceptive processing. Due to the observed regional and psychopathological specificity, their findings bear important clinical implications for the potential treatment strategy.

Topics

Anxiety, Depression, Psychometrics, Treatment, Cognitive Processes Functional Brain Connectivity Studies Neural dynamics and brain function

Categories

Cognitive Neuroscience Life Sciences Neuroscience

Tags

Anxiety Functional magnetic resonance imaging Fusiform gyrus Generalized anxiety disorder Hippocampus Medicine Neuroscience Panic disorder Psychiatry Psychology Psychopathology Resting state fMRI

Conditions & symptoms

Anxiety Panic disorder and phobias Anxiety or worry Panic