Biological psychiatry
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Biological psychiatry · Aug 1999
Comparative Study Clinical Trial Controlled Clinical TrialA double-blind comparison of lorazepam and oxazepam in psychomotor retardation and mutism.
An increasing number of case reports indicate a superior therapeutic response of catatonialike symptoms, such as severe psychomotor disturbance and mutism, associated with psychiatric disorder to the benzodiazepine lorazepam (LO). Equivocal results, however, are also reported with regard to other benzodiazepines for the treatment of this syndrome. The purpose of this study was to compare the effects of LO and oxazepam (OX), benzodiazepines with comparable pharmacokinetics, on psychomotor retardation and mutism associated with psychiatric disorder. ⋯ Both OX and LO are effective for the treatment of psychomotor retardation. Thus, the beneficial effect of LO on psychomotor retardation and mutism is not a unique pharmacodynamic property but more likely due to its pharmacokinetic profile. The differential effect of the two benzodiazepines on the second day of treatment warrants further clarification. Several hypotheses are evaluated.
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Biological psychiatry · Jul 1999
Randomized Controlled Trial Clinical TrialThe effect of acute tryptophan depletion and fenfluramine on quantitative EEG and mood in healthy male subjects.
Efforts to model putative serotonergic deficits associated with affective disorders have frequently involved acute tryptophan depletion (ATD) as a manipulation strategy aimed at lowering brain serotonin synthesis. In an attempt to widen the scope of the measurement probes used in these investigations, the central actions of ATD and a subsequent dose of fenfluramine were examined via utilization of quantitative electroencephalography (EEG) and mood ratings. ⋯ Quantitative EEG measurements may be a promising method for studying the central mechanisms underlying serotonin-mediated changes in mood and behavior.
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Biological psychiatry · May 1999
A.E. Bennett Research Award. Developmental traumatology. Part II: Brain development.
Previous investigations suggest that maltreated children with a diagnosis of posttraumatic stress disorder (PTSD) evidence alterations of biological stress systems. Increased levels of catecholaminergic neurotransmitters and steroid hormones during traumatic experiences in childhood could conceivably adversely affect brain development. ⋯ These data suggest that the overwhelming stress of maltreatment experiences in childhood is associated with adverse brain development.
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Biological psychiatry · Apr 1999
Heightened transcription for enzymes involved in norepinephrine biosynthesis in the rat locus coeruleus by immobilization stress.
The locus coeruleus (LC), a target for CRH neurons, is critically involved in responses to stress. Various physiological stresses increase norepinephrine turnover, tyrosine hydroxylase (TH) enzymatic activity, protein and mRNA levels in LC cell bodies and terminals; however, the effect of stress on other enzymes involved in norepinephrine biosynthesis in the LC is unknown. ⋯ This study is the first to reveal transcriptional activation of the genes encoding catecholamine biosynthetic enzymes in the LC by stress. In addition to TH, changes in DBH and GTPCH gene expression may also contribute to the development of stress-triggered affective disorders.
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Biological psychiatry · Jan 1999
ReviewThe reduced neuropil hypothesis: a circuit based model of schizophrenia.
In recent years, quantitative studies of the neuropathology of schizophrenia have reignited interest in the cerebral cortex and focused attention on the cellular and subcellular constituents that may be altered in this disease. Findings have ranged from compromised circuitry in prefrontal areas to outright neuronal loss in temporal and cingulate cortices. Herein, we propose that a reduction in interneuronal neuropil in the prefrontal cortex is a prominent feature of cortical pathology in schizophrenia and review the growing evidence for this view from reports of altered neuronal density and immunohistochemical markers in various cortical regions. The emerging picture of neuropathology in schizophrenia is one of subtle changes in cellular architecture and brain circuity that nonetheless have a devastating impact on cortical function.