Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
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Neuropsychopharmacology · May 2006
Randomized Controlled Trial Comparative Study Clinical TrialA randomized, placebo-controlled trial of OROS methylphenidate in adults with attention-deficit/hyperactivity disorder.
The objective of this study was to evaluate the safety and efficacy of once-daily OROS methylphenidate (MPH) in the treatment of adults with DSM-IV attention-deficit/hyperactivity disorder (ADHD). ⋯ These results show that treatment with OROS MPH in daily doses of up to 1.3 mg/kg/day was effective in the treatment of adults with ADHD. Because of the potential for increases in blood pressure and heart rate, subjects receiving treatment with MPH should be monitored for changes in blood pressure parameters during treatment.
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Neuropsychopharmacology · May 2006
The striatal and extrastriatal D2/D3 receptor-binding profile of clozapine in patients with schizophrenia.
Positron emission tomography (PET) studies reveal that clozapine at clinically used doses occupies less than 60% of D2/D3 dopamine receptors in human striatum. Here, the occupancy of D2/D3 dopamine receptors by clozapine in patients with schizophrenia was determined to test the hypothesis that clozapine binds preferentially to extrastriatal dopamine receptors. A total of 15 clozapine-treated inpatients with schizophrenia underwent a [18F]fallypride PET scan. ⋯ Occupancy of cortical receptors approaches 60% with plasma clozapine in the range 350-400 ng/ml, which corresponds to the threshold for antipsychotic efficacy of clozapine. Extrastriatal binding of clozapine may be more relevant to its antipsychotic actions than striatal. However, further studies with an intraindividual comparison of untreated vs treated state are desirable to confirm this finding.
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Neuropsychopharmacology · May 2006
Systemic and intra-amygdala administration of glucocorticoid agonist and antagonist modulate extinction of conditioned fear.
We examined the effect of glucocorticoid agonists on the extinction of conditioned fear in rats by using fear-potentiated startle. Systemic injection of glucocorticoid receptor agonists dexamethasone (DEX) (0.1, 0.5, and 1.0 mg/kg) and intra-amygdala infusion of RU28362 (0.5, 1.0, and 3.0 ng/side) prior to extinction training facilitated extinction of conditioned fear in a dose-dependent manner. Extinction of conditioned fear and circulating corticosterone levels were attenuated by administration of corticosteroid synthesis inhibitor metyrapone (25 mg/kg s.c.) 90 min before extinction training. ⋯ The Dose of dexamethsone or metyrapone used here did not influence fear-potentiated startle when administered before testing. Thus, it is unlikely that these drugs influenced extinction by increasing or disrupting CS processing. All results suggested that amygdaloid glucocorticoid receptors were involved in the extinction of conditioned fear.