1. ¹Department of Molecular Neurobiochemistry, International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
2. ²Section of Neuroimaging, Institute of Psychiatry, De Crespigny Park, London, UK
3. ³Department of Neurochemistry, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
4. ⁴The Psychiatric Clinic, Vasant Vihar, New Delhi, India

Correspondence: Dr S Bhattacharyya, Section of Neuroimaging, PO 67, Institute of Psychiatry, De Crespigny Park, London SE5 8AF, UK. Tel: +44 20 7848 0355; Fax: +44 20 7848 0976; E-mail: s.bhattacharyya@iop.kcl.ac.uk

⁵Previously: Department of Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore 560029, India.

Received 1 June 2004; Revised 13 January 2005; Accepted 21 February 2005; Published online 20 April 2005.

Abstract

The role of glutamatergic dysfunction in the pathophysiology of OCD has hardly been explored despite recent reports implicating glutamatergic dysfunction in OCD. We decided to investigate CSF glutamate levels in adult OCD probands compared to psychiatrically normal controls. In total, 21 consenting psychotropic drug-naïve adult OCD patients, diagnosed using SCID-IV-CV, and 18 consenting psychiatrically normal controls with age within 10 years of age of the patients, who did not have any history of head injury or neurological illness, were included into the study. Aseptically collected and stored CSF samples obtained from the patients and control subjects were used for glutamate estimation, which was carried out by a modification of the procedure described by Lund (1986). CSF glutamate (mol/l) level was found to be significantly higher [F(1,31)=6.846, p=0.014] in OCD patients (47.124.25) compared to control subjects (41.363.63) on analysis of covariance. There was no effect of gender, age, duration of illness, Y-BOCS score, or CGI-S score on CSF glutamate levels. Our study provides preliminary evidence implicating glutamatergic excess in the pathophysiology of OCD, which needs to be further explored by studies from other centers involving larger sample sets from different age groups.