Brain structural abnormalities in behavior therapy-resistant obsessive-compulsive disorder revealed by voxel-based morphometry

Figures & data

Table 1 Demographic and clinical findings of OCD patients (n=39) and healthy participants (n=30)

	Responders (n=24) (A)	Nonresponders (n=15) (B)	Healthy participants (n=30) (C)	P
	Mean (SD)	Mean (SD)	Mean (SD)
Age, years	35.7 (7.2)	32.5 (7.7)	32.5 (6.7)	0.208
Sex (male, %)	45.8	46.6	46.6	ns
Years of education	14.4 (1.5)	13.6 (1.8)	14.1 (1.5)	0.322
Duration of illness, years	6.3 (3.2)	5.2 (2.5)	(−)	0.250
SRI, mg/day (clomipramine equivalent)	220.8 (25.1)	243.3 (41.6)	(−)	0.070
BDI-II	16.1 (6.3)	15.4 (7.3)	1.9 (1.2)	<0.001 A=B>C
STAI
State anxiety	49.6 (10.8)	55.8 (11.2)	27.1 (4.5)	<0.001 A=B>C
Trait anxiety	54.2 (12.1)	61.1 (11.8)	33.6 (4.1)	<0.001 A=B>C
Y-BOCS
Total	33.3 (4.2)	33.1 (5.3)	(−)	0.844
Obsessions	16.7 (2.1)	16.8 (2.9)	(−)	0.927
Compulsions	16.5 (2.6)	16.2 (2.7)	(−)	0.644
Brain volumes
TIV, mL	1,604.5 (87.9)	1,568.3 (124.1)	1,611.4 (134.6)	0.501
GM volume, mL	669.8 (10.5)	642.0 (13.3)	655.4 (9.4)	0.256
WM volume, mL	456.6 (47.2)	496.5 (85.3)	469.5 (58.1)	0.158

Notes: The male/female ratio was compared using a chi-square test (χ²). (−) No data.

Abbreviations: BDI-II, Beck Depression Inventory-II; GM, gray matter; ns, not significant; OCD, obsessive-compulsive disorder; SD, standard deviation; SRI, serotonin reuptake inhibitors; STAI, State-Trait Anxiety Inventory; TIV, total intracranial volume; WM, white matter; Y-BOCS, Yale-Brown Obsessive Compulsive Scale.

Table 2 Clinical findings before and after behavior therapy in the OCD groups (n=39)

	Pre-treatment	Post-treatment	P
	Mean (SD)	Mean (SD)
Responders (n=24)
Y-BOCS
Total	33.3 (4.2)	16.0 (3.3)	<0.001
Obsessions	16.7 (2.1)	8.1 (1.7)	<0.001
Compulsions	16.5 (2.6)	7.8 (2.0)	<0.001
BDI-II	16.1 (6.3)	15.9 (5.7)	0.698
STAI
State anxiety	51.5 (12.2)	38.9 (9.5)	<0.001
Trait anxiety	52.2 (11.0)	45.5 (8.9)	<0.001
Nonresponders (n= 15)
Y-BOCS
Total	33.0 (5.3)	30.0 (5.5)	0.012
Obsessions	16.8 (2.9)	15.6 (3.4)	0.031
Compulsions	16.2 (2.7)	14.9 (2.3)	0.029
BDI-II	15.4 (7.3)	15.0 (6.8)	0.417
STAI
State anxiety	55.8 (11.2)	54.8 (11.2)	0.610
Trait anxiety	61.1 (11.8)	60.4 (12.6)	0.056

Abbreviations: BDI-II, Beck Depression Inventory-II; OCD, obsessive-compulsive disorder; SD, standard deviation; STAI, State-Trait Anxiety Inventory; Y-BOCS, Yale-Brown Obsessive Compulsive Scale.

Figure 1 (A) Smaller regional GM volumes were observed for the right orbitofrontal cortex and left cingulate cortex in nonresponder OCD patients (n=15), compared with responder OCD patients (n=24). (B) Smaller regional WM volumes were observed for the left cingulate bundle in nonresponder OCD patients (n=15), compared with responder OCD patients (n=24).

Abbreviations: GM, gray matter; OCD, obsessive-compulsive disorder; WM, white matter.

Table 3 Areas with smaller regional GM and WM volumes in nonresponder OCD patients (n=15) than in responder OCD patients (n=24)

Region	Brodmann’s area	Talairach coordinate (mm)			Voxels in cluster	T-value
		x	y	z
Rt ventromedial prefrontal cortex	25	1	14	−14	3,476	6.55
Rt orbitofrontal cortex	11	8	25	−16	3,476	4.93
Rt orbitofrontal cortex	11	7	25	−24	3,476	3.85
Rt precentral gyrus	6	56	2	39	944	6.39
Rt precentral gyrus	6	60	−3	28	944	4.22
Rt precentral gyrus	6	58	−5	37	944	3.69
Lt anterior cingulate cortex	24	−3	3	27	805	5.06
Lt cingulate bundle		−4	4	38	1,328	4.99
Lt cingulate bundle		−1	18	26	1,328	4.85
Lt cingulate bundle		−1	11	30	1,328	4.50
Lt superior frontal white matter		−31	−13	48	928	5.82
Lt superior frontal white matter		−25	−5	47	928	4.11

Notes: FDR set at 0.05. Results of a voxel-wise SPM analysis.

Abbreviations: FDR, false discovery rate; GM, gray matter; Lt, left; OCD, obsessive-compulsive disorder; Rt, right; SPM, statistical parametric mapping; WM, white matter.

Table 4 Areas with smaller regional GM and WM volumes in nonresponder OCD patients (n=15) than in healthy participants (n=30)

Region	Brodmann’s area	Talairach coordinate (mm)			Voxels in cluster	T-value
		x	y	z
Rt thalamus		3	−5	0	2,486	4.87
Rt caudate		6	0	4	2,486	4.54
Lt posterior cingulate cortex	30	−21	−59	9	1,707	8.28
Lt posterior cingulate cortex	30	−14	−65	10	1,707	4.79
Rt inferior frontal white matter		17	57	−13	1,178	5.90
Rt inferior frontal white matter		11	53	−13	1,178	5.14
Rt inferior frontal white matter		13	40	−19	1,178	4.84
Lt cingulate bundle		−25	−60	14	1,142	4.51

Notes: FDR set at 0.05. Results of a voxel-wise SPM analysis.

Abbreviations: FDR, false discovery rate; GM, gray matter; Lt, left; OCD, obsessive-compulsive disorder; Rt, right; SPM, statistical parametric mapping; WM, white matter.

Table 5 Areas with smaller regional GM and WM volumes in responder OCD patients (n=24) than in healthy participants (n=30)

Region	Brodmann’s area	Talairach coordinate (mm)			Voxels in cluster	T-value
		x	y	z
Lt dorsolateral prefrontal	8	−52	10	40	848	7.17
Lt dorsolateral prefrontal	8	−39	21	42	848	6.50
Lt superior frontal white matter		−30	−11	47	948	6.37
Lt superior frontal white matter		−36	−17	55	948	5.26

Notes: FDR set at 0.05. Results of a voxel-wise SPM analysis.

Abbreviations: FDR, false discovery rate; GM, gray matter; Lt, left; OCD, obsessive-compulsive disorder; SPM, statistical parametric mapping; WM, white matter.