title: LOWER POSTERIOR CINGULATE CORTEX GLUTATHIONE LEVELS IN OBSESSIVE-COMPULSIVE DISORDER.
abstract: BACKGROUND
  Several lines of evidence support the hypothesis that lower cerebral levels of glutathione (GSH), associated with increased oxidative stress, may contribute to obsessive-compulsive disorder (OCD). However, no studies to date have investigated brain GSH levels in individuals with OCD.
  
  
  METHODS
  Twenty-nine individuals with OCD and 25 age-, sex-, and race-matched comparison individuals without OCD underwent single voxel 2D J-resolved proton magnetic resonance spectroscopy (MRS) to examine GSH levels in the posterior cingulate cortex (PCC). MRS data were analyzed using LCModel and a simulated basis set. Group metabolite differences referenced to total creatine (Cr), as well as relationships between metabolite ratios and symptom severity as measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), were analyzed using linear regression with adjustment for age, sex, and race.
  
  
  RESULTS
  One OCD participant failed to produce usable PCC MRS data. We found significantly lower PCC GSH/Cr in OCD participants compared with non-OCD participants (β = -0.027 [95% CI: -0.049 to -5.9 × 10-3];P= 0.014). PCC GSH/Cr was not significantly associated with total Y-BOCS score in the OCD group (β = 5.7 × 10-4[95% CI: -4.8 × 10-3to 5.9 × 10-3];P= 0.83).
  
  
  CONCLUSIONS
  Lower PCC GSH/Cr may be indicative of increased oxidative stress secondary to hypermetabolism in this brain region in OCD. Future MRS studies are warranted to investigate GSH levels in other brain regions that comprise the cortico-striato-thalamo-cortical circuit thought to be abnormal in OCD.
authors.affiliation: Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA; Obsessive-Compulsive Disorders Institute, McLean Hospital, Belmont, MA; Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Brennan
authors.affiliation: Department of Psychiatry, Harvard Medical School, Boston, MA; McLean Imaging Center, McLean Hospital, Belmont, MA.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Jensen
authors.affiliation: Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA.
authors.forename: Christine
authors.initials: C
authors.lastname: Perriello
authors.affiliation: Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA; Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Harrison G
authors.initials: HG
authors.lastname: Pope
authors.affiliation: Obsessive-Compulsive Disorders Institute, McLean Hospital, Belmont, MA; Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Jenike
authors.affiliation: Biological Psychiatry Laboratory, McLean Hospital, Belmont, MA; Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: James I
authors.initials: JI
authors.lastname: Hudson
authors.affiliation: Department of Psychiatry, Harvard Medical School, Boston, MA.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Rauch
authors.affiliation: Department of Psychiatry, Harvard Medical School, Boston, MA; McLean Imaging Center, McLean Hospital, Belmont, MA.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Kaufman
keywords: MRS; OCD; glutathione; obsessive-compulsive disorder; oxidative stress; posterior cingulate cortex