Deficits in auditory P50 inhibition in obsessive-compulsive disorder.
Obsessive-compulsive disorder (OCD) is considered to involve abnormalities in inhibitory processes including gating systems. Auditory P50 inhibition, which is assessed by using a paired auditory stimulus paradigm to record P50 mid-latency evoked potential, is assumed to reflect sensory gating. In the present study, we investigated auditory P50 inhibition in subjects with OCD, and examined the relationship between P50 and clinical variables or neuropsychological performance. Twenty-six subjects with OCD and 26 age- and sex-matched healthy controls received P50 recording and neuropsychological tests. In the OCD subjects, we also evaluated clinical features including OC symptoms and subtypes of the disorder. P50 T/C ratios were significantly higher in OCD subjects than in control subjects (t=2.9, df=50, p=0.006). Compared to the controls, the OCD subjects performed significantly worse on the Symbol Digit Modalities Test (SDMT) and the Trail Making Test (TMT). There were no correlations between P50 T/C ratios and clinical variables or the results of neuropsychological tests. Our findings suggest that sensory gating deficits may be involved in the pathophysiology of OCD in a different way from clinical symptoms and executive attention dysfunction.
Hashimoto
Tasuku
T
Department of Psychiatry, Chiba University Graduate School of Medicine, Chiba, Japan.
Shimizu
Eiji
E
Koike
Kaori
K
Orita
Yasuhiro
Y
Suzuki
Tomotaka
T
Kanahara
Nobuhisa
N
Matsuzawa
Daisuke
D
Fukami
Goro
G
Miyatake
Ryosuke
R
Shinoda
Naoyuki
N
Fujisaki
Mihisa
M
Shirayama
Yukihiko
Y
Hashimoto
Kenji
K
Iyo
Masaomi
M
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000503:physiopathology*; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D018709:Statistics, Nonparametric