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Preclinical evidence suggests that diazepam enhances hippocampal γ-aminobutyric acid (GABA) signalling and normalises a psychosis-relevant cortico-limbic-striatal circuit. Hippocampal network dysconnectivity, particularly from the CA1 subfield, is evident in people at clinical high-risk for psychosis (CHR-P), representing a potential treatment target. This study aimed to forward-translate this preclinical evidence.
Methods
In this randomised, double-blind, placebo-controlled study, 18 CHR-P individuals underwent resting-state functional magnetic resonance imaging twice, once following a 5 mg dose of diazepam and once following a placebo. They were compared to 20 healthy controls (HC) who did not receive diazepam/placebo. Functional connectivity (FC) between the hippocampal CA1 subfield and the nucleus accumbens (NAc), amygdala, and ventromedial prefrontal cortex (vmPFC) was calculated. Mixed-effects models investigated the effect of group (CHR-P placebo/diazepam vs. HC) and condition (CHR-P diazepam vs. placebo) on CA1-to-region FC.
Results
In the placebo condition, CHR-P individuals showed significantly lower CA1-vmPFC (Z = 3.17, PFWE = 0.002) and CA1-NAc (Z = 2.94, PFWE = 0.005) FC compared to HC. In the diazepam condition, CA1-vmPFC FC was significantly increased (Z = 4.13, PFWE = 0.008) compared to placebo in CHR-P individuals, and both CA1-vmPFC and CA1-NAc FC were normalised to HC levels. In contrast, compared to HC, CA1-amygdala FC was significantly lower contralaterally and higher ipsilaterally in CHR-P individuals in both the placebo and diazepam conditions (lower: placebo Z = 3.46, PFWE = 0.002, diazepam Z = 3.33, PFWE = 0.003; higher: placebo Z = 4.48, PFWE < 0.001, diazepam Z = 4.22, PFWE < 0.001).
Conclusions
This study demonstrates that diazepam can partially restore hippocampal CA1 dysconnectivity in CHR-P individuals, suggesting that modulation of GABAergic function might be useful in the treatment of this clinical group.
Next-generation X-ray satellite telescopes such as XRISM, NewAthena and Lynx will enable observations of exotic astrophysical sources at unprecedented spectral and spatial resolution. Proper interpretation of these data demands that the accuracy of the models is at least within the uncertainty of the observations. One set of quantities that might not currently meet this requirement is transition energies of various astrophysically relevant ions. Current databases are populated with many untested theoretical calculations. Accurate laboratory benchmarks are required to better understand the coming data. We obtained laboratory spectra of X-ray lines from a silicon plasma at an average spectral resolving power of $\sim$7500 with a spherically bent crystal spectrometer on the Z facility at Sandia National Laboratories. Many of the lines in the data are measured here for the first time. We report measurements of 53 transitions originating from the K-shells of He-like to B-like silicon in the energy range between $\sim$1795 and 1880 eV (6.6–6.9 Å). The lines were identified by qualitative comparison against a full synthetic spectrum calculated with ATOMIC. The average fractional uncertainty (uncertainty/energy) for all reported lines is ${\sim}5.4 \times 10^{-5}$. We compare the measured quantities against transition energies calculated with RATS and FAC as well as those reported in the NIST ASD and XSTAR’s uaDB. Average absolute differences relative to experimentally measured values are 0.20, 0.32, 0.17 and 0.38 eV, respectively. All calculations/databases show good agreement with the experimental values; NIST ASD shows the closest match overall.
Clinical guidelines for personality disorder emphasise the importance of patients being supported to develop psychological skills to help them manage their symptoms and behaviours. But where these mechanisms fail, and hospital admission occurs, little is known about how episodes of acutely disturbed behaviour are managed.
Aims
To explore the clinical characteristics and management of episodes of acutely disturbed behaviour requiring medication in in-patients with a diagnosis of personality disorder.
Method
Analysis of clinical audit data collected in 2024 by the Prescribing Observatory for Mental Health, as part of a quality improvement programme addressing the pharmacological management of acutely disturbed behaviour. Data were collected from clinical records using a bespoke proforma.
Results
Sixty-two mental health Trusts submitted data on 951 episodes of acutely disturbed behaviour involving patients with a personality disorder, with this being the sole psychiatric diagnosis in 471 (50%). Of the total, 782 (82%) episodes occurred in female patients. Compared with males, episodes in females were three times more likely to involve self-harming behaviour or be considered to pose such a risk (22% and 70% respectively: p < 0.001). Parenteral medication (rapid tranquillisation) was administered twice as often in episodes involving females than in males (64 and 34% respectively: p < 0.001).
Conclusions
Our findings suggest that there are a large number of episodes of acutely disturbed behaviour on psychiatric wards in women with a diagnosis of personality disorder. These episodes are characterised by self-harm and regularly prompt the administration of rapid tranquillisation. This has potential implications for service design, staff training, and research.
This chapter gives a detailed and rigorous treatment of Markov decision processes, which are a foundational framework for dynamic programming. Numerous examples are discussed.
This chapter introduces key concepts from dynamic programming via a simple job search example with IID wage draws. We also discuss numerical methods and fixed-point techniques.
This chapter gives a rigorous treatment of optimal stopping in discrete time. We also consider numerical and analytical methods using continuation value techniques.