Distinguishing quantitative electroencephalogram findings between panic disorder and generalized anxiety disorder
H.-S. Suh1, K.-S. Lee2
1Suh Yonsei Psychiatry Clinic, Psychiatry, Seoul, Korea, Republic of, 2School of Medicine, CHA University, Bundang Medical Center, Psychiatry, Seongnam, Korea, Republic of
Background: Generalized anxiety disorder and panic disorder are common diagnoses in anxiety disorders. Both disorders share similar symptoms such as apprehensive expectation, physical presentation of anxiety, and persistent concern or worry. generalized anxiety disorder is probably the disorder that most often coexists with another anxiety disorder and of persons with panic disorder 15 to 30 percent have generalized anxiety disorder.
Aims & Objectives: In order to clearly differentiate generalized anxiety disorder and panic disorder, using electro physiological studies such as quantitative analysis of an electro encephalogram(EEG) or evoked potential electroencephalogram of anxiety may inform treatment decisions and prognostic assessments as a potential indicator of brain dysfunction. The aim of this study is to determine the distinguishing neurophysiological characteristics between generalized anxiety disorder and panic disorder using quantitative EEG.
Method: The subjects of this study were 36 patients with generalized anxiety disorder (8 men and 28 women; mean age: 47.1 years) and 25 patients with panic disorder (7 men and 18 women; mean age: 42.0 years). The patients were diagnosed through semi-structured clinical interviews based on the DSM-V by psychiatrists.
Quantitative EEG recording and data processing: Resting (eye closed) vigilance controlled EEG recordings were assessed at 64 electrode sites according to the international 10/20 system. Quantitative EEG were compared between generalized anxiety disorder and panic disorder groups by frequency bands (delta 1-4 Hz, theta 4-8 Hz, alpha 8-12 Hz, beta 12-25 Hz, high beta 25-30 Hz, gamma 30-40 Hz and total 1-40 Hz) made by spectral analysis.
Quantitative EEG recording and data processing: Resting (eye closed) vigilance controlled EEG recordings were assessed at 64 electrode sites according to the international 10/20 system. Quantitative EEG were compared between generalized anxiety disorder and panic disorder groups by frequency bands (delta 1-4 Hz, theta 4-8 Hz, alpha 8-12 Hz, beta 12-25 Hz, high beta 25-30 Hz, gamma 30-40 Hz and total 1-40 Hz) made by spectral analysis.
Results: The absolute powers of theta and alpha bands at the frontal area differed between generalized anxiety disorder and panic disorder group. The absolute power of the theta activity was decreased at FP1 and FP2 (p<0.05) and the absolute power of the alpha activity was decreased at F3 (p<0.05) in cases with generalized anxiety disorder compared to panic disorder.
Even though the absolute powers of high beta bands (25-30 Hz) between generalized anxiety disorder and panic disorder group showed no significant differences, the absolute powers of 29 and 30 Hz were decreased at Pz and P4 area (p<0.05) in cases with generalized anxiety disorder compared to panic disorder.
Even though the absolute powers of high beta bands (25-30 Hz) between generalized anxiety disorder and panic disorder group showed no significant differences, the absolute powers of 29 and 30 Hz were decreased at Pz and P4 area (p<0.05) in cases with generalized anxiety disorder compared to panic disorder.
Discussion & Conclusions: The differences in quantitative EEG power in our investigation suggest that underlying pathophysiologic mechanisms may be different between generalized anxiety disorder and panic disorder. The findings that the decreased absolute powers of the theta and alpha activity at the frontal area in generalized anxiety disorder may be the main neurophysiological characteristics of the generalized anxiety disorder.
The present study further suggests that these differences in quantitative EEG between generalized anxiety disorder and panic disorder are potentially useful neurobiological marker for distinguishing differential diagnosis findings between generalized anxiety disorder and panic disorder.
The present study further suggests that these differences in quantitative EEG between generalized anxiety disorder and panic disorder are potentially useful neurobiological marker for distinguishing differential diagnosis findings between generalized anxiety disorder and panic disorder.
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