Smaller amygdala is associated with anxiety in patients with panic disorder.
OBJECTIVE
Anxiety a core feature of panic disorder, is linked to function of the amygdala. Volume alterations in the brain of patients with panic disorder have previously been reported, but there has been no report of amygdala volume association with anxiety.


METHODS
Volumes of hippocampus and amygdala were manually measured using magnetic resonance imaging obtained from 27 patients with panic disorder and 30 healthy comparison subjects. In addition the amygdala was focused on, applying small volume correction to optimized voxel-based morphometry (VBM). State-Trait Anxiety Inventory and the NEO Personality Inventory Revised were also used to evaluate anxiety.


RESULTS
Amygdala volumes in both hemispheres were significantly smaller in patients with panic disorder compared with control subjects (left: t = -2.248, d.f. = 55, P = 0.029; right: t = -2.892, d.f. = 55, P = 0.005). VBM showed that structural alteration in the panic disorder group occurred on the corticomedial nuclear group within the right amygdala (coordinates [x,y,z (mm)]: [26,-6,-16], Z score = 3.92, family-wise error-corrected P = 0.002). The state anxiety was negatively correlated with the left amygdala volume in patients with panic disorder (r = -0.545, P = 0.016).


CONCLUSIONS
These findings suggested that the smaller volume of the amygdala may be associated with anxiety in panic disorder. Of note, the smaller subregion in the amygdala estimated on VBM could correspond to the corticomedial nuclear group including the central nucleus, which may play a crucial role in panic attack.
Hayano
Fumi
F
Department of Psychiatry, Graduate School of Medicine, Yokohama City University, Kanagawa, Japan.
Nakamura
Motoaki
M
Asami
Takeshi
T
Uehara
Kumi
K
Yoshida
Takeshi
T
Roppongi
Tomohide
T
Otsuka
Tatsui
T
Inoue
Tomio
T
Hirayasu
Yoshio
Y
D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000473:pathology*; D001007:Anxiety / Q000473:pathology*; D016022:Case-Control Studies; D005260:Female; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D007031:Hypothalamus / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000473:pathology*; D011569:Psychiatric Status Rating Scales