Obsessive Compulsive Disorder
- Epidemiology
- Comorbidity
- OCD and Tic Disorder
- OCD and Depression
- OCD and Other Anxiety Disorders
- OCD and Phobia
- OCD and OCPD
- OCD and Schizophrenia
- Course and Prognosis
- Etiology
- Specific Clinical Response
- Serotonin Antagonists
- Pharmacological Challenges
- Dopamine
- Immune Factors
- Brain Imaging Studies
- Genetics
- Other Biological Data
- Behavioral Factors
- Psychosocial Factors
- Treatment of OCD
- Efficacy of Serotonergic vs Adrenergic Antidepressants
- Long Term Treatment of OCD
- Drug Dosage
- Psychological Approaches
- Treatment Resistant OCD
- Switching Medications
- Augmentation
- Risperidone
- Pindolol
- Other Options
- Intravenous Clomipramine
- Monoamine Oxidase Inhibitors
- Last-line Therapies
Brain Imaging Studies for OCD
Positron emission tomography (PET) has displayed increased activity (i.e. metabolism and blood flow) in the frontal lobes, the basal ganglia (especially the caudate nucleus), and the cingulum of OCD patients. Pharmacological and behavioral treatments reportedly reverse those abnormalities. The data from functional imaging studies are consistent with the data from structural brain-imaging studies. Both computed tomographic and magnetic resonance imaging studies have found decreased sizes of caudates bilaterally. Both functional and structural imaging procedures are consistent with the observation that neurological procedures involving the cingulum are sometimes effective in the treatment of OCD patients. Overall, the brain imaging research suggests a role for the prefrontal cortex-basal ganglia thalamic circuitry. Dysfunction of these circuits can be explored by neuropsychological testing and evoked potentials. A recent study of OCD patients showed that they are slower in performing tasks involving frontocortical systems, suggesting alterations at this level. An evoked potential study showed enhanced processing negativity in the frontal cortex consistent with prefrontal hyperactivity shown in brain imaging studies.