European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
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Eur Neuropsychopharmacol · Apr 2019
Clinical TrialFunctional connectivity between prefrontal cortex and subgenual cingulate predicts antidepressant effects of ketamine.
Converging evidence suggests that a single sub-anesthetic dose of ketamine can produce strong and rapid antidepressant effects in patients that do not respond to standard treatment. Despite a considerable amount of research investigating ketamine's mechanisms of action, the exact neuronal targets conveying the antidepressant effects have not been identified yet. Preclinical studies suggest that molecular changes induced by ketamine bring forward large-scale network reconfigurations that might relate to ketamine's antidepressant properties. ⋯ Our results show that FC increases after ketamine between right lateral prefrontal cortex (PFC) and subgenual anterior cingulate cortex (sgACC) are positively linked to treatment response. Furthermore, low baseline FC between these regions predicts treatment outcome. We conclude that PFC-sgACC connectivity may represent a promising biomarker with both predictive and explanatory power.
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Eur Neuropsychopharmacol · Mar 2019
ReviewA systematic review of phytocannabinoid exposure on the endocannabinoid system: Implications for psychosis.
Cannabis, the most widely used illicit drug worldwide, produces psychoactive effects through its component cannabinoids, which act on the endocannabinoid system. Research on how cannabinoid exposure affects the endocannabinoid system is limited. Substantial evidence indicates cannabis use as a risk factor for psychosis, and the mechanism(s) by which this is occurring is/are currently unknown. ⋯ The most well established finding is the down-regulation of cannabinoid CB1 receptors (CB1R) after chronic and recent cannabis exposure, but it remains uncertain whether this effect is present in cannabis users with schizophrenia. We highlight where cannabis exposure affects the endocannabinoid system in a pattern that may mirror what is seen in psychosis, and how further research can push this field forward. In these times of changing cannabis legislation, research highlighting the biological effects of cannabinoids is greatly needed.
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Eur Neuropsychopharmacol · Dec 2018
Spicing it up - synthetic cannabinoid receptor agonists and psychosis - a systematic review.
Synthetic cannabinoid receptor agonists (SCRAs) are suggested to have increased potential to induce psychosis compared to natural cannabis (NC). In this review we synthesise current knowledge about the association of SCRA use with psychotic symptoms. Following a literature search we identified 2 toxicology reports, 4 case-control studies, 3 cross-sectional studies and 15 case reports. ⋯ The case reports supported the association of SCRA use with a wide range of positive and negative psychotic symptoms as well as with self-harm, agitation and aggressive behaviour. SCRA use is relatively prevalent in patients with psychosis and may lead to psychotic symptoms in individuals with no past psychiatric history. Further work is required to understand the long term risks of SCRA use and optimal management strategies.
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Eur Neuropsychopharmacol · Jul 2018
Randomized Controlled TrialModulation of acute effects of delta-9-tetrahydrocannabinol on psychotomimetic effects, cognition and brain function by previous cannabis exposure.
Cannabis use has been associated with psychosis and cognitive dysfunction. Some evidence suggests that the acute behavioral and neurocognitive effects of the main active ingredient in cannabis, (-)-trans-Δ9-tetrahydrocannabinol (∆9-THC), might be modulated by previous cannabis exposure. However, this has not been investigated either using a control group of non-users, or following abstinence in modest cannabis users, who represent the majority of recreational users. ⋯ Under ∆9-THC, cannabis users showed brain activity patterns intermediate between those in non-users under placebo (control group), and non-users under ∆9-THC (acute effect) and cannabis users under placebo (residual effect). In non-users, the more severe the ∆9-THC-induced psychotomimetic symptoms and cognitive impairments, the more pronounced was the neurophysiological alteration (all P≤0.036). Previous modest cannabis use blunts the acute behavioral and neurophysiological effects of ∆9-THC, which are more marked in people who have never used cannabis.
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Eur Neuropsychopharmacol · Jun 2018
Randomized Controlled TrialPLACID study: A randomized trial comparing the efficacy and safety of inhaled loxapine versus intramuscular aripiprazole in acutely agitated patients with schizophrenia or bipolar disorder.
The aim of the study was to investigate the efficacy and safety of inhaled loxapine compared with the intramuscular (IM) antipsychotic aripiprazole in acutely agitated patients with schizophrenia or bipolar I disorder. PLACID was an assessor-blind, parallel-group trial conducted in 23 centres in the Czech Republic, Germany, Spain, and Russia. Patients (aged 18-65 years) diagnosed with schizophrenia or bipolar I disorder experiencing acute agitation (Clinical Global Impression [CGI]-Severity score ≥ 4) while hospitalized or attending an emergency room were randomized to receive up to two doses of inhaled loxapine 9.1 mg or IM aripiprazole 9.75 mg (≥ 2 h between doses) during the 24-h study period. ⋯ The between-treatment difference in median time to CGI-Improvement response was 10 min (95% CI 0.0-30.0); p = 0.0005) in favour of inhaled loxapine (median [95% CI]: 50 min [30.0-50.0] vs 60 min [50.0-90.0] with IM aripiprazole); the difference was significant at 10 min (responders: 14% [loxapine] vs 4% [aripiprazole]; p = 0.001). There were no safety issues. Inhaled loxapine reduced agitation faster than IM aripiprazole, supporting its use as a first-line option for managing acute agitation in patients with schizophrenia or bipolar disorder.