European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
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Eur Neuropsychopharmacol · Oct 2015
Role of the nitric oxide donor sodium nitroprusside in the antidepressant effect of ketamine in mice.
Ketamine may represent an efficient alternative antidepressant with rapid therapeutic onset; however, the clinical use of ketamine is hampered by psychosis-like side-effects. Recent studies suggest that the nitric oxide (NO) donor sodium nitroprusside (SNP) prevents psychosis-like abnormalities triggered by ketamine or another NMDA receptor (NMDAR) antagonist, phencyclidine (PCP) in rats. SNP was shown to elicit antipsychotic effects also in humans. ⋯ We found that SNP (0.5-1mg/kg, i.p.) did not alter the antidepressant effect of ketamine (30 mg/kg) in the Porsolt Forced Swim Test (FST) in mice. Additionally, SNP by itself produced no effect in the FST or in the openfield. This suggests indirectly a differential involvement of the nitrinergic system in the antidepressant vs. psychotomimetic effect of ketamine, although an influence of species-specific differences cannot be excluded in this interpretation.
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Eur Neuropsychopharmacol · Oct 2015
Associations of hippocampal metabolism and regional brain grey matter in neuroleptic-naïve ultra-high-risk subjects and first-episode schizophrenia.
Hippocampal pathology has been shown to be central to the pathophysiology of schizophrenia and a putative risk marker for developing psychosis. We applied both (1)H MRS (proton magnetic resonance spectroscopy) at 3Tesla and voxel-based morphometry (VBM) of high-resolution brain structural images in order to study the association of the metabolites glutamate (Glu) and N-acetyl-aspartate (NAA) in the hippocampus with whole-brain morphometry in 31 persons at ultra-high-risk for psychosis (UHR), 18 first-episode schizophrenia patients (Sz), and 42 healthy controls (all subjects being neuroleptic-naïve). ⋯ For NAA, we observed different associations for left prefrontal and caudate clusters bilaterally for both high-risk and first-episode schizophrenia subjects, diverging from the pattern seen in healthy subjects. Our results suggest that associations of hippocampal metabolites in key areas of schizophrenia might vary due to liability to or onset of the disorder.
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Eur Neuropsychopharmacol · Oct 2015
Benzodiazepines and risk of death: Results from two large cohort studies in France and UK.
Benzodiazepines are widely prescribed for the treatment of anxiety or insomnia, but their impact on mortality is still debated. This study investigated the impact of benzodiazepine use on short term mortality. Exposed-unexposed cohorts were constructed with the Clinical Practice Research Datalink (CPRD) in the UK and with the General Sample of Beneficiaries (EGB) in France. ⋯ When considering benzodiazepine use as a time-dependent covariate, adjusted HR for current use at 12 months was 1.03 (0.74-1.44). Using two nationally representative databases, we found a significant while moderate increase in all-cause mortality in relation to benzodiazepines, in a population of incident and mostly occasional users. This issue need to be monitored given the extensive use of these drugs.