Rapid effects of brief intensive cognitive-behavioral therapy on brain glucose metabolism in obsessive-compulsive disorder.

Brief intensive cognitive-behavioral therapy (CBT) using exposure and response prevention significantly improves obsessive-compulsive disorder (OCD) symptoms in as little as 4 weeks. However, it has been thought that much longer treatment was needed to produce the changes in brain function seen in neuroimaging studies of OCD. We sought to elucidate the brain mediation of response to brief intensive CBT for OCD and determine whether this treatment could induce functional brain changes previously seen after longer trials of pharmacotherapy or standard CBT. [(18)F]-fluorodeoxyglucose positron emission tomography brain scans were obtained on 10 OCD patients before and after 4 weeks of intensive individual CBT. Twelve normal controls were scanned twice, several weeks apart, without treatment. Regional glucose metabolic changes were compared between groups. OCD symptoms, depression, anxiety and overall functioning improved robustly with treatment. Significant changes in normalized regional glucose metabolism were seen after brief intensive CBT (P=0.04). Compared to controls, OCD patients showed significant bilateral decreases in normalized thalamic metabolism with intensive CBT but had a significant increase in right dorsal anterior cingulate cortex activity that correlated strongly with the degree of improvement in OCD symptoms (P=0.02). The rapid response of OCD to intensive CBT is mediated by a distinct pattern of changes in regional brain function. Reduction of thalamic activity may be a final common pathway for improvement in OCD, but response to intensive CBT may require activation of dorsal anterior cingulate cortex, a region involved in reappraisal and suppression of negative emotions.

Cerebral metabolism in major depression and obsessive-compulsive disorder occurring separately and concurrently.

BACKGROUND: The frequent comorbidity of major depressive disorder (MDD) and obsessive-compulsive disorder (OCD) suggests a fundamental relationship between them. We sought to determine whether MDD and OCD have unique cerebral metabolic patterns that remain the same when they coexist as when they occur independently. METHODS: [18F]-fluorodeoxyglucose positron emission tomography (PET) brain scans were obtained on 27 subjects with OCD alone, 27 with MDD alone, 17 with concurrent OCD+MDD, and 17 normal control subjects, all in the untreated state. Regional cerebral glucose metabolism was compared between groups. RESULTS: Left hippocampal metabolism was significantly lower in subjects with MDD alone and in subjects with concurrent OCD+MDD than in control subjects or subjects with OCD alone. Hippocampal metabolism was negatively correlated with depression severity across all subjects. Thalamic metabolism was significantly elevated in OCD alone and in MDD alone. Subjects with concurrent OCD+MDD had significantly lower metabolism in thalamus, caudate, and hippocampus than subjects with OCD alone. CONCLUSIONS: Left hippocampal dysfunction was associated with major depressive episodes, regardless of primary diagnosis. Other cerebral metabolic abnormalities found in OCD and MDD occurring separately were not seen when the disorders coexisted. Depressive episodes occurring in OCD patients may be mediated by different basal ganglia-thalamic abnormalities than in primary MDD patients.

Personality changes in adult subjects with major depressive disorder or obsessive-compulsive disorder treated with paroxetine.

BACKGROUND: Human and animal studies point to 3 dimensions of personality that change during pharmacotherapy with a selective serotonin reuptake inhibitor (SSRI). Specifically, harm avoidance has been found to decrease, social dominance has been found to increase, and hostility in social situations has been found to decrease with SSRI treatment. We sought to determine personality changes in subjects with either major depressive disorder (MDD) or obsessive-compulsive disorder (OCD) treated with paroxetine. We also sought to determine whether or not these personality changes were associated with disease state (MDD vs. OCD) or treatment response (responders vs. nonresponders). METHOD: Thirty-seven subjects diagnosed with either MDD or OCD (according to DSM-IV criteria) completed the Cattell 16 Personality Factor Inventory (16-PF) before and after treatment with paroxetine. Treatment response was defined as a Clinical Global Impressions-Improvement rating of "much" or "very much" improved and a drop in Hamilton Rating Scale for Depression score of at least 50% for MDD or Yale-Brown Obsessive Compulsive Scale score of at least 30% for OCD. RESULTS: No significant differences were found between subjects with MDD and OCD in personality change with treatment. In the whole group, treatment responders had a greater decrease than nonresponders in 16-PF factors relating to harm avoidance. An increase in social dominance factors and a decrease in factors relating to hostility in social situations were found, but these changes were not significantly different between responders and nonresponders. CONCLUSION: These findings indicate that certain personality dimensions change with SSRI treatment and that some of these changes are independent of clinical treatment response.

Localized orbitofrontal and subcortical metabolic changes and predictors of response to paroxetine treatment in obsessive-compulsive disorder.

Previous positron emission tomography (PET) studies of patients with obsessive-compulsive disorder (OCD) have found elevated glucose metabolic rates in the orbitofrontal cortex (OFC) and caudate nuclei that normalize with response to treatment. Furthermore, OCD symptom provocation differentially activates specific subregions of the OFC, which have distinct patterns of connectivity and serve different functions. Therefore, we sought to determine the role of specific subregions of the OFC and associated subcortical structures in mediating OCD symptoms, by determining how glucose metabolism in these structures changed with paroxetine treatment of OCD patients. We also sought to determine whether pretreatment OFC metabolism would predict response to paroxetine, as it has for other OCD treatments. Twenty subjects with OCD received [18F]-fluorodeoxyglucose (FDG)-PET scans before and after 8 to 12 weeks of treatment with paroxetine, 40 mg/day. In patients who responded to paroxetine, glucose metabolism decreased significantly in right anterolateral OFC and right caudate nucleus. Lower pretreatment metabolism in both left and right OFC predicted greater improvement in OCD severity with treatment. These results add to evidence indicating that orbitofrontal-subcortical circuit function mediates the symptomatic expression of OCD. Specific subregions of the OFC may be differentially involved in the pathophysiology of OCD and/or its response to pharmacotherapy.