Cortical functional activity in patients with generalized anxiety disorder

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Neurological underpinnings of Generalized Anxiety Disorder (GAD) remain largely unknown.
• Existing evidence suggests cortical dysregulation in GAD patients.
• Electroencephalogram (EEG) nonlinear analysis offers a novel approach to investigate cortical function.

Purpose of the Study:

• To examine cortical functional activity in GAD patients using EEG nonlinear analysis.
• To evaluate the contribution of nonlinear parameters to anxiety severity.
• To identify specific cerebral regions affected by GAD.

Main Methods:

• Sixty-four GAD patients and 30 healthy controls underwent EEG.
• Patients were categorized into mild and moderate-severe anxiety groups based on Hamilton Rating Scale for Anxiety (HAMA) scores.
• Nonlinear parameter Correlation Dimension (D2) was analyzed, and its association with HAMA scores was assessed via regression analysis.

Main Results:

• GAD patients exhibited increased D2 values compared to controls (P < .05).
• Mild anxiety showed increased D2 in left prefrontal regions; moderate-severe anxiety showed increased D2 across most regions, notably left cerebral and right temporal lobes.
• A positive correlation was found between D2 values and moderate-severe anxiety HAMA scores.

Conclusions:

• Increased D2 values in GAD patients, particularly in left cerebral regions and the right temporal lobe, indicate widespread cortical dysfunction.
• Higher anxiety severity correlates with increased D2 values in more cerebral regions.
• EEG nonlinear analysis shows potential as a complementary tool for assessing cortical activity in GAD.