Effects of intensive cognitive-behavioral therapy on cingulate neurochemistry in obsessive-compulsive disorder.

The neurophysiological bases of cognitive-behavioral therapy (CBT) for obsessive-compulsive disorder (OCD) are incompletely understood. Previous studies, though sparse, implicate metabolic changes in pregenual anterior cingulate cortex (pACC) and anterior middle cingulate cortex (aMCC) as neural correlates of response to CBT. The goal of this pilot study was to determine the relationship between levels of the neurochemically interlinked metabolites glutamate + glutamine (Glx) and N-acetyl-aspartate + N-acetyl-aspartyl-glutamate (tNAA) in pACC and aMCC to pretreatment OCD diagnostic status and OCD response to CBT. Proton magnetic resonance spectroscopic imaging ((1)H MRSI) was acquired from pACC and aMCC in 10 OCD patients at baseline, 8 of whom had a repeat scan after 4 weeks of intensive CBT. pACC was also scanned (baseline only) in 8 age-matched healthy controls. OCD symptoms improved markedly in 8/8 patients after CBT. In right pACC, tNAA was significantly lower in OCD patients than controls at baseline and then increased significantly after CBT. Baseline tNAA also correlated with post-CBT change in OCD symptom severity. In left aMCC, Glx decreased significantly after intensive CBT. These findings add to evidence implicating the pACC and aMCC as loci of the metabolic effects of CBT in OCD, particularly effects on glutamatergic and N-acetyl compounds. Moreover, these metabolic responses occurred after just 4 weeks of intensive CBT, compared to 3 months for standard weekly CBT. Baseline levels of tNAA in the pACC may be associated with response to CBT for OCD. Lateralization of metabolite effects of CBT, previously observed in subcortical nuclei and white matter, may also occur in cingulate cortex. Tentative mechanisms for these effects are discussed. Comorbid depressive symptoms in OCD patients may have contributed to metabolite effects, although baseline and post-CBT change in depression ratings varied with choline-compounds and myo-inositol rather than Glx or tNAA.

Augmentation of serotonin reuptake inhibitors in refractory obsessive-compulsive disorder using adjunctive olanzapine: a placebo-controlled trial.

BACKGROUND: The purpose of this study was to explore the efficacy of adding an atypical antipsychotic, olanzapine, to a serotonin reuptake inhibitor (SRI) in treatment-refractory obsessive-compulsive disorder (OCD). METHOD: Twenty-six patients aged between 18 and 65 (mean = 41.2, SD = 11.9) years meeting DSM-IV criteria for OCD, who had not responded to SRIs, were treated for 6 weeks in a double-blind, placebo-controlled augmentation study with either olanzapine (up to 20 mg/day) or placebo. Severity of illness was assessed biweekly by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Analysis of covariance with baseline Y-BOCS score included as a covariate was used to compare improvement in Y-BOCS scores in the 2 groups. Response was defined as a 25% or greater improvement in Y-BOCS score. Data were collected between April 2001 and May 2003. RESULTS: Outcome was assessed for all patients using the last observation carried forward. Subjects in the olanzapine group had a mean decrease of 4.2 (SD = 7.9) in Y-BOCS score compared with a mean increase in score of 0.54 (SD = 1.31) for subjects in the placebo group (F = 4.85, df = 2,23; p =.04). Six (46%) of 13 subjects in the olanzapine group showed a 25% or greater improvement in Y-BOCS score compared with none in the placebo group. The final mean dose of olanzapine was 11.2 (SD = 6.5) mg/day. Medication was well tolerated. Only 2 (15%) of 13 subjects who received olanzapine discontinued because of side effects: sedation (N = 1) or weight gain (N = 1). CONCLUSION: These results provide preliminary evidence that adding olanzapine to SRIs is potentially efficacious and well tolerated in the short-term treatment of patients with refractory OCD. Controlled studies with larger sample sizes are necessary to more definitively address this treatment strategy.