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The low-frequency linearly polarised radio source population is largely unexplored. However, a renaissance in low-frequency polarimetry has been enabled by pathfinder and precursor instruments for the Square Kilometre Array. In this second paper from the POlarised GaLactic and Extragalactic All-Sky MWA Survey-the POlarised GLEAM Survey, or POGS-we present the results from our all-sky MWA Phase I Faraday Rotation Measure survey. Our survey covers nearly the entire Southern sky in the Declination range
at a resolution between around three and seven arcminutes (depending on Declination) using data in the frequency range 169−231 MHz. We have performed two targeted searches: the first covering 25 489 square degrees of sky, searching for extragalactic polarised sources; the second covering the entire sky South of Declination
, searching for known pulsars. We detect a total of 517 sources with 200 MHz linearly polarised flux densities between 9.9 mJy and 1.7 Jy, of which 33 are known radio pulsars. All sources in our catalogues have Faraday rotation measures in the range
rad m−2. The Faraday rotation measures are broadly consistent with results from higher-frequency surveys, but with typically more than an order of magnitude improvement in the precision, highlighting the power of low-frequency polarisation surveys to accurately study Galactic and extragalactic magnetic fields. We discuss the properties of our extragalactic and known-pulsar source population, how the sky distribution relates to Galactic features, and identify a handful of new pulsar candidates among our nominally extragalactic source population.
This study examined the link between two biological markers of stress vulnerability at 22–26 years of age and telomere length at 30–35 among extremely low birth weight (ELBW; <1000 g) survivors and normal birth weight (NBW; >2500 g) control participants. Sixteen ELBW and 22 NBW participants provided baseline afternoon salivary cortisol samples and resting frontal electroencephalogram (EEG) alpha asymmetry data at 22–26 years. Buccal cells were assayed for telomere length at 30–35 years. Analyses controlled for sex, postnatal steroid exposure, childhood socioeconomic status, time of cortisol sample collection, and body mass index at 22–26 years. Salivary cortisol and frontal asymmetry at age 22–26 independently predicted telomere length at age 30–35, such that relatively higher cortisol and greater relative right frontal asymmetry at rest predicted telomere shortening among NBW controls, but not among ELBW survivors. However, similar associations were not noted in ELBW survivors, suggesting that ELBW survivors may have different mechanisms of stress coping as a result of their early-life exposures. These findings offer preliminary evidence in support of the role of stress in the genesis of cellular senescence at least among those born at NBW, but that these links may differ in those born preterm.
While polypharmacy is common in long-term residential psychiatric patients, prescription combinations may, from an evidence-based perspective, be irrational. Potentially, many psychiatric patients are treated on the basis of a poor diagnosis. We therefore evaluated the DITSMI model (i.e., Diagnose, Indicate, and Treat Severe Mental Illness), an intervention that involves diagnosis (or re-diagnosis) and appropriate treatment for severely mentally ill long-term residential psychiatric patients. Our main objective was to determine whether DITSMI affected changes over time regarding diagnoses, pharmacological treatment, psychosocial functioning, and bed utilization.
DITSMI was implemented in a consecutive patient sample of 94 long-term residential psychiatric patients during a longitudinal cohort study without a control group. The cohort was followed for three calendar years. Data were extracted from electronic medical charts. As well as diagnoses, medication use and current mental status, we assessed psychosocial functioning using the Health of the Nations Outcome Scale (HoNOS). Bed utilization was assessed according to length of stay (LOS). Change was analyzed by comparing proportions of these data and testing them with chi-square calculations. We compared the numbers of diagnoses and medication changes, the proportions of HoNOS scores below cut-off, and the proportions of LOS before and after provision of the protocol.
Implementation of the DITSMI model was followed by different diagnoses in 49% of patients, different medication in 67%, some improvement in psychosocial functioning, and a 40% decrease in bed utilization.
Our results suggest that DITSMI can be recommended as an appropriate care for all long-term residential psychiatric patients.
Recent evidence has questioned modern psychiatric clinical practice, specifically the prescribing of “atypical” antipsychotics. Our Pan-European Research Group wished to ascertain clinical practice amongst European trainees, which treatments trainees would desire for themselves, and factors influencing this.
A semi-structured survey was constructed from prior literature, piloted, and a homogenous sample size of at least 50 was agreed upon from each country, with 50% minimum response rate. It was distributed via web-link, with questions on preference of antipsychotic for patients in given scenarios, and factors influencing choice. Physicians were asked for their preference should they develop psychosis.
i) Treatment choice of antipsychotic for patients
93% (n=600) of respondents chose to prescribe “atypical” antipsychotics (excluding Clozapine), 6% (n=42) choosing “typical” antipsychotics, 1% (n=6) choosing Clozapine as first-line therapy.
ii) Treatment choice if trainees developed psychosis
89% (n=530) of responders chose to prescribe “atypical” antipsychotics (excluding Clozapine), 7% (n=40) choosing “typical” antipsychotics, 4% (n=23) choosing Clozapine as first-line therapy.
iii) Factors influencing choice
These mapped onto three domains: cost, efficacy and side-effect profile (less than 5% other reasons). 79% (n=458) of those who responded felt efficacy most important, 46% (n=270) felt side-effect profile most important and 3% (n=16) considered cost of paramount importance.
38% (n=272) of those who responded to the survey stated that the CATIE trial had influenced their decision-making.
Psychiatry trainees’ choice of antipsychotic medication for both patients and themselves is based on perceived benefits, as opposed to evidence base and recent literature.
Guidelines produced for management of Bipolar Disorder illustrate change in evidence-base for treatment of acute and maintenance phases of illness. Our Pan-European Research Group assessed clinical practice and desired treatments amongst amongst Psychiatry trainees.
A semi-structured survey was piloted, and homogenous sample size (at least 50) agreed upon from each country, with 50% minimum response rate. It was distributed via web-link, questioning preference of mood stabiliser for patients, trainees themselves and factors influencing choice.
Tables 1 summarise choices.
Lithium and Sodium Valproate
2nd Generation Atypical antipsychotics
[Choice of mood stabiliser for patient/themselves]
Factors influencing decision-making mapped onto cost, efficacy and side-effect profile (less than 4% other reasons). 66% (n=538) of respondents felt efficacy most important, 25% (n=202) felt side-effect profile most important and 3% (n=24) considered cost of most importance.
No clear difference exists in choice of mood stabiliser for European trainees and their patients, and decisions based on perceived efficacy are generally in keeping with established guidelines.
The rat model of prenatal restraint stress (PRS) is particularly valuable to study the mechanisms involved in the pathophysiology of anxiety/depression since adult PRS rats show endocrine and behavioral abnormalities that are corrected by antidepressant medication. We have previously shown that agomelatine chronic treatment reversed the anxiety behaviour and decreased hippocampal neurogenesis observed in PRS. Here, we investigated the mechanisms that may contribute to the antidepressant activity of agomelatine, by assessing the effects of a chronic treatment with agomelatine on neurobiological markers of neuroplasticity in the rat hippocampus such as BDNF and its receptor, TrkB, the transcription factor pCREB and metabotrophic glutamate receptors (mGluRs). Adult SD control and PRS rats were treated chronically with agomelatine (40mg/kg ip) or vehicle. 16h after last drug administration, animals were sacrificed and hippocampus dissected for biochemical analysis.
PRS animals showed reduced levels of pCREB in the hippocampus and increased hippocampal BDNF, and TrkB receptor levels. Agomelatine reversed changes in pCREB and BDNF/TrkB levels in PRS rats, had no effect on pCREB in control rats, and, interestingly, increased BDNF and TrkB receptor levels in control rats. Moreover, agomelatine reversed the reduced expression (for mGluR5 and mGluR2/3 receptors) and function (for mgluR5 receptor) observed in the hippocampus of PRS rats.
In conclusion, we have shown that agomelatine treatment reversed all biochemical and cellular changes induced by PRS in rats. These changes, independently of their direction, are the expression of an enduring maladaptive form of neuroplasticity that may contribute to the depressive/anxious phenotype of PRS rats.
There is growing concern about the influence of the pharmaceutical industry on psychiatric teaching and psychiatric professionalism as a whole. As a consequence, several national and international medical and psychiatric associations have issued guidelines to regulate the interactions between physicians and industry.
The EFPT-PRIRS study aims to provide the lacking data on the extent and nature of these interactions among psychiatric trainees across Europe.
Study objectives were determined by the EFPT research group (EFPT-RG), after discussion with national and international experts. A survey was then devised compiling previously published questionnaires extending them by questions with specific relevance to psychiatric trainees. The resulting questionnaire was piloted amongst members of the EFPT-RG, modified accordingly and subsequently distributed to the national study coordinators. All 24 EFPT member countries were invited to participate in the study and data collection is currently ongoing.
Preliminary analysis reveals the vast differences in industry - trainee relationships across European countries as well as major differences in personal attitudes towards these interactions.
EFPT-PRIRS will potentially have an impact on the regulation of the interactions between the pharmaceutical industry and psychiatric trainees.
Frequent use of cannabis has been associated with poor outcome in patients with psychosis or schizophrenia, and research has become more and more interested in the question whether cannabis may actually cause psychosis or schizophrenia. Since only a minority of cannabis users eventually develops psychosis or schizophrenia, cannabis is suggested to be a component cause, potentially interacting with environmental as well as genetic factors. However, little is known about this putative interaction. Recent research in our group has therefore focused on differential sensitivity to cannabis and its psychosis-inducing effects. Experimental and observational work for instance showed that a functional polymorphism within the COMT gene moderates the acute effects of cannabis on psychosis outcome. In this presentation new evidence from epidemiological work is presented, showing gene-environment interactions within the cannabis-psychosis association. These results point to a moderating role for both age of onset of cannabis use and childhood trauma. Also a certain haplotype within the COMT gene was found to increase the risk of developing schizophrenia after adolescent cannabis use. Complex gene-environment interactions as well as interactions between cannabis and other environmental risk factors seem to underlie the cannabis-psychosis relationship. Possible biological mechanisms such as sensitization processes that may underlie these interactions will be discussed.
Research suggests that cannabis use negatively impacts on onset and outcome of schizophrenia. Possible effects in mood disorders have received little investigation. The first study analysing the influence of cannabis exposure on clinical and social treatment outcomes within a bipolar disorder (BP) population during 1 year of treatment is presented.
3684 patients were enrolled in an observational study when psychotropic treatment for mania was initiated/changed. The influence of cannabis exposure on baseline-corrected clinical and social treatment outcome measures was examined. Mediating effects of six variables on associations between cannabis and outcome measures were investigated further.
Over 12 months of treatment, cannabis users exhibited higher levels of BP overall illness severity, mania and psychosis, and less severe depression symptoms compared to non-users. These associations were most frequently mediated by abuse of alcohol and other substances. Users more frequently abused alcohol and other substances; these associations were not mediated by other variables. Cannabis users engaged in more social activities but had a higher probability of not having a relationship and fewer dependents to care for. Associations with activities and dependents to care for were mediated by various variables, whereas no variables mediated the association with not having a relationship.
Cannabis use impacts on clinical outcomes in patients with BP, with a modest impact on social outcomes. More research is required to further elucidate the mechanism by which cannabis exerts its influence. Understanding the associations between cannabis use and outcome measures may offer valuable insights into treatment strategies.
It has been observed that children with auditory hallucinations (AH) may develop secondary delusional ideation, which is thought to increase the risk of need for care and patient status. Little is known about the cognitive vulnerabilities mediating delusion formation in children experiencing perceptual anomalies like AH. The ability to correctly interpret another person's intentions or emotions, referred to as mentalizing ability or ‘theory of mind’ (ToM), is shown to be impaired in children with psychotic symptoms and to be associated with delusional ideation in individuals at risk. A direct link between mentalizing ability and delusions is suggested by their presentation as alterations in social inference.
To examine the cognitive vulnerabilities mediating delusion formation in children presenting with AH.
In a sample of 259 12- and 13-year-old children, AH, delusional experiences (’mind reading’,’paranoid ideas’ and’receiving media messages’) and theory of mind (ToM) were assessed, in order to examine the hypothesized moderating role of ToM in delusion formation.
The risk of delusion formation was significantly higher in AH children with lower ToM skills (OR = 2.9, 95% CI 1.3–6.4, P = 0.008), compared to AH children with higher ToM skills (OR = 1.7, 95% CI 0.9–3.4, P = 0.11).
Our results suggest that better mentalizing abilities confer protection against developing full-blown psychosis in children experiencing perceptual anomalies.
Victimization in childhood may be associated with adult psychosis. This association was examined cross-sectional and longitudinal in the crucial developmental period of early adolescence.
Data were derived from standard health screenings of the Youth Health Care Divisions of the Municipal Health Services in Maastricht, the Netherlands. A self-report questionnaire was filled out by a total of 1290 adolescents to assess non-clinical psychotic experiences, as well as experiences of being bullied, sexual trauma and life events.
The cross-sectional study showed that unwanted sexual experiences and being bullied were strongly and independently associated with psychotic experiences. In the same sample, it was shown that sexual trauma increased the risk for psychotic symptoms two years later. Life events contributed to the risk for psychosis over time and psychosis in turn gave rise to new life events. No significant association with bullying was found after controlling for confounders.
These results suggest that reported associations between childhood victimization and adult psychosis can be understood in a developmental framework of onset of at-risk mental states in early adolescence. Early and later psychological stress, if severe, may impact on the risk for psychosis in adolescence trough mechanisms of person-environment interaction and correlation.
Despite recent recent evidence and subsequent guidelines that have suggested factors such as side-effect profile and cost should be taken into account when prescribing antidepressant medication, relatively little evidence exists on decision-making in clinical practice.
Our Pan-European Research Group looked at clinical practice regarding antidepressants amongst Psychiatry trainees, treatments trainees would desire themselves, and factors influencing decision-making.
A semi-structured survey was constructed from recent literature, was piloted, and a homogenous sample size of at least 50 agreed upon from each country, with 50% the minimum response rate. It was distributed via web-link, questioning preference of antidepressant for patients, and factors influencing choice. Trainees were asked for their preference should they develop a moderate to severe depressive episode, and require medication.
Treatment choices are summarised in Table 1. 79% of trainees would prescribe similar antidepressants for themselves as for patients.
Factors influencing decision-making mapped onto three main domains: cost, efficacy and side-effect profile (5% other reasons). 86% (n = 548) of those who responded felt efficacy most important, 38% (n = 237) felt side-effect profile most important and 6% (n = 33) considered cost of most importance.
Some differences exist in choice of antidepressant for European trainees and their patients, and factors affecting choice conflict with evidence base and guideline suggestions.
In a baseline study among 7–8 year old children with auditory vocal hallucinations (AVH), only limited functional impact of AVH was observed.
To assess AVH 5-year course and its predictors, as well as AVH 5-year incidence and its risk factors.
A sample of 337 12- and 13-year-old children were reassessed on AVH after a mean follow-up period of 5.1 years. Parents completed the Child Behaviour Checklist (CBCL). School performance was assessed.
The AVH 5-year persistence and incidence rates were 24% and 9% respectively, more new cases arising in urban areas. Both persistent and incident AVH were associated with problem behaviour in the (CBCL) clinical range, particularly at follow-up, as well as with other psychosis-like symptoms, particularly at baseline. AVH persistence was predicted by baseline AVH severity, notably in terms of external attribution of voices and hearing multiple voices, and was associated with worse primary school test scores and lower level secondary school.
First-onset AVH in middle childhood is neither rare nor neutral in terms of psychopathological and behavioural comorbidity. Persistence of AVH in early childhood similarly is not rare and associated with psychopathological, behavioural and cognitive alterations.
Auditory vocal hallucinations (AVH) in general had limited functional impact in 7–8 year old children. However, transitory developmental expression of psychotic symptoms may become more persistent (and clinically relevant), depending on the degree of exposure to environmental risk factors. Therefore, in a five-year follow-up study of a case-control sample associations of (severity of) AVH with social adversity (traumatic experiences and stressful events) and the formation of delusional ideation were examined. In total 337 children (mean age 13.1 years; SD = 0.5) were reassessed. Forty children had continued to hear voices (24%, persistent group), 15 had heard voices for the first time (9%, incident group), 130 children no longer reported AVH (remitted group) and 152 never heard voices (referent group). Early social adversity was strongly associated with both incident and persistent AVH, and predicted greater AVH severity at follow-up. Children with both AVH and delusions were more likely to have experienced traumatic or stressful events than children with either symptom alone. AVH severity was shown to be a mediator in the association between TE (but not SE) and delusion formation. These results suggest that, although hearing voices in 7–8 year olds is in most cases benign, experience of social adversity can predict persistence and onset of new AVH closer to puberty. Given evidence for the association with delusion formation, they do pose a significant clinical risk.
General population studies have found that the positive symptoms of psychosis are prevalent in the general population. The majority of the individuals experiencing these “symptoms” are not in need of care. However, longitudinal studies indicate that they may nevertheless have an increased risk of developing a clinical disorder. The aim of this study is to elucidate the mechanisms that mediate transition from having one or two psychotic symptoms to becoming a patient with a psychotic disorder.
Data from two large longitudinal general population studies (the NEMESIS study and the EDSP study) were analysed in order to investigate the risk-increasing effect of three important environmental risk factors, namely cannabis, urbanicity, and childhood trauma, as well as their interaction with pre-existing liability to psychosis.
Based on these studies, cannabis not only survives as a risk factor for psychosis, but the evidence is showing concrete synergistic effects between cannabis and pre-existing psychosis liability. The urban environment is, in terms of attributable risk, the most important proxy environmental risk factor and there is emerging evidence that it interacts with genetic risk. Early trauma is another important aspect of the environment that can be linked prospectively to psychosis, particularly for those with a pre-existing liability.
The mechanism by which the environment is likely to impact on risk is through cognitive and emotional pathways on the one hand, and biological pathways, possibly involving dopamine sensitisation, on the other.