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Mass asymptomatic SARS-CoV-2 nucleic acid amplified testing of healthcare personnel (HCP) was performed at a large tertiary health system. A low period-prevalence of positive HCP was observed. Of those who tested positive, half had mild symptoms in retrospect. HCP with even mild symptoms should be isolated and tested.
We assessed long-term incidence and prevalence trends of dementia and parkinsonism across major ethnic and immigrant groups in Ontario.
Linking administrative databases, we established two cohorts (dementia 2001–2014 and parkinsonism 2001–2015) of all residents aged 20 to 100 years with incident diagnosis of dementia (N = 387,937) or parkinsonism (N = 59,617). We calculated age- and sex-standardized incidence and prevalence of dementia and parkinsonism by immigrant status and ethnic groups (Chinese, South Asian, and the General Population). We assessed incidence and prevalence trends using Poisson regression and Cochran–Armitage trend tests.
Across selected ethnic groups, dementia incidence and prevalence were higher in long-term residents than recent or longer-term immigrants from 2001 to 2014. During this period, age- and sex-standardized incidence of dementia in Chinese, South Asian, and the General Population increased, respectively, among longer-term immigrants (by 41%, 58%, and 42%) and long-term residents (28%, 7%, and 4%), and to a lesser degree among recent immigrants. The small number of cases precluded us from assessing parkinsonism incidence trends. For Chinese, South Asian, and the General Population, respectively, prevalence of dementia and parkinsonism modestly increased over time among recent immigrants but significantly increased among longer-term immigrants (dementia: 134%, 217%, and 117%; parkinsonism: 55%, 54%, and 43%) and long-term residents (dementia: 97%, 132%, and 71%; parkinsonism: 18%, 30%, and 29%). Adjustment for pre-existing conditions did not appear to explain incidence trends, except for stroke and coronary artery disease as potential drivers of dementia incidence.
Recent immigrants across major ethnic groups in Ontario had considerably lower rates of dementia and parkinsonism than long-term residents, but this difference diminished with longer-term immigrants.
Three holes were drilled to the bed of Rutford Ice Stream, through ice up to 2154 m thick, to investigate the basal processes and conditions associated with fast ice flow and the glacial history of the West Antarctic Ice Sheet. A narrative of the drilling, measuring and sampling activities, as well as some preliminary results and initial interpretations of subglacial conditions, is given. These were the deepest subglacial access holes ever drilled using the hot-water drilling method. Samples of bed and englacial sediments were recovered, and a number of instruments were installed in the ice column and the bed. The ice–bed interface was found to be unfrozen, with an existing, well-developed subglacial hydrological system at high pressure, within ~1% of the ice overburden. The bed itself comprises soft, water-saturated sediments, consistent with previous geophysical interpretations. Englacial sediment quantity varies significantly between two locations ~2 km apart, and possibly over even shorter (~20 m) distances. Difficulties and unusual observations encountered while connecting to the subglacial hydrological system in one hole possibly resulted from the presence of a large clast embedded in the bottom of the ice.
There has been relatively limited work focused on understanding whether relatives of individuals with bipolar disorder (BD) have difficulties in the regulation of emotion, particularly in relation to perceptions about whether emotions can be effectively regulated, or trait behaviours that acknowledge emotions as self-regulators themselves. In this study, we assessed the presence and extent of difficulties in these dimensions of emotion regulation in individuals with BD compared to unaffected first-degree biological relatives (FDR) for the first time.
In total, 161 participants, including euthymic individuals with BD, unaffected FDRs, and healthy controls, were compared on the Difficulties in Emotion Regulation Scale (DERS) – a multi-dimensional measure of habitual emotion regulation. Clinical data were also collected and examined in relation to DERS scores in a secondary analysis.
In the BD group, difficulties were evident for most dimensions of emotion regulation as measured by the DERS; and correlated with an earlier onset of illness and more mood episodes. FDRs displayed generally normal emotion regulation, except in terms of their beliefs that emotions can be effectively regulated; on this dimension, their reported difficulty was intermediate to the BD group and controls.
Habitual emotion regulation difficulties in BD persist irrespective of mood state, are related to the course of illness, and should be targeted in psychological interventions. Further, the perception that emotions cannot be effectively regulated during times of distress seems to represent an endophenotype for BD.
The value of services for those with the ‘At Risk Mental State for Psychosis’ (ARMS) continues to be disputed. ARMS services have provided a valuable stimulus to academic research into the transition into psychosis. Furthermore, there is currently a welcome trend to transform such clinics into youth mental health services catering for the broader clientele of young people suffering from anxiety and depression, who already constitute the bulk of those seen at ARMS clinics. However, such services are never likely to make major inroads into preventing psychosis because they only reach a small proportion of those at risk. Evidence from medicine shows that avoiding exposure to factors which increase the risk of disease (e.g. poor nutrition, transmission of infection, tobacco smoking), produces greater public benefit than focussing efforts on individuals with, or about to develop, disease. We consider that the most productive approach for psychosis prevention is avoiding exposure to risk-increasing factors. The best-established risk factors for psychosis are obstetric events, childhood abuse, migration, city living, adverse life events and cannabis use. Some as city living, are likely proxies for an unknown causal factor(s) while preventing others such as childhood abuse is currently beyond our powers. The risk factor for psychosis which is most readily open to this approach is the use of cannabis. Therefore, as an initial step towards a strategy for universal primary prevention, we advocate public health campaigns to educate young people about the harms of regular use of high potency cannabis.
Parasites sometimes expand their host range and cause new disease aetiologies. Genetic changes can then occur due to host-specific adaptive alterations, particularly when parasites cross between evolutionarily distant hosts. Characterizing genetic variation in Cryptosporidium from humans and other animals may have important implications for understanding disease dynamics and transmission. We analyse sequences from four loci (gp60, HSP-70, COWP and actin) representing multiple Cryptosporidium species reported in humans. We predicted low genetic diversity in species that present unusual human infections due to founder events and bottlenecks. High genetic diversity was observed in isolates from humans of Cryptosporidium meleagridis, Cryptosporidium cuniculus, Cryptosporidium hominis and Cryptosporidium parvum. A deviation of expected values of neutrality using Tajima's D was observed in C. cuniculus and C. meleagridis. The high genetic diversity in C. meleagridis and C. cuniculus did not match our expectations but deviations from neutrality indicate a recent decrease in genetic variability through a population bottleneck after an expansion event. Cryptosporidium hominis was also found with a significant Tajima's D positive value likely caused by recent population expansion of unusual genotypes in humans. These insights indicate that changes in genetic diversity can help us to understand host-parasite adaptation and evolution.
To disrupt cycles of health inequity, traceable to dietary inequities in the earliest stages of life, public health interventions should target improving nutritional wellbeing in preconception/pregnancy environments. This requires a deep engagement with pregnant/postpartum people (PPP) and their communities (including their health and social care providers, HSCP). We sought to understand the factors that influence diet during pregnancy from the perspectives of PPP and HSCP, and to outline intervention priorities.
We carried out thematic network analyses of transcripts from ten focus group discussions (FGD) and one stakeholder engagement meeting with PPP and HSCP in a Canadian city. Identified themes were developed into conceptual maps, highlighting local priorities for pregnancy nutrition and intervention development.
FGD and the stakeholder meeting were run in predominantly lower socioeconomic position (SEP) neighbourhoods in the sociodemographically diverse city of Hamilton, Canada.
All local, comprising twenty-two lower SEP PPP and forty-three HSCP.
Salient themes were resilience, resources, relationships and the embodied experience of pregnancy. Both PPP and HSCP underscored that socioeconomic-political forces operating at multiple levels largely determined the availability of individual and relational resources constraining diet during pregnancy. Intervention proposals focused on cultivating individual and community resilience to improve early-life nutritional environments. Participants called for better-integrated services, greater income supports and strengthened support programmes.
Hamilton stakeholders foregrounded social determinants of inequity as main factors influencing pregnancy diet. They further indicated a need to develop interventions that build resilience and redistribute resources at multiple levels, from the household to the state.
It remains poorly understood how negative symptoms are experienced in the daily lives of individuals in the early stages of psychosis. We aimed to investigate whether altered affective experience, anhedonia, social anhedonia, and asociality were more pronounced in individuals with an at-risk mental state for psychosis (ARMS) and individuals with first-episode psychosis (FEP) than in controls.
We used the experience sampling methodology (ESM) to assess negative symptoms, as they occurred in the daily life of 51 individuals with FEP and 46 ARMS, compared with 53 controls.
Multilevel linear regression analyses showed no overall evidence for a blunting of affective experience. There was some evidence for anhedonia in FEP but not in ARMS, as shown by a smaller increase of positive affect (BΔat−risk v. FEP = 0.08, p = 0.006) as the pleasantness of activities increased. Against our expectations, no evidence was found for greater social anhedonia in any group. FEP were more often alone (57%) than ARMS (38%) and controls (35%) but appraisals of the social situation did not point to asociality.
Overall, altered affective experience, anhedonia, social anhedonia and asociality seem to play less of a role in the daily life of individuals in the early stages of psychosis than previously assumed. With the experience of affect and pleasure in daily life being largely intact, changing social situations and appraisals thereof should be further investigated to prevent development or deterioration of negative symptoms.
Tuberculosis (TB) in children is a critical public health issue. In Bohol, Philippines, we found a high tuberculin skin test (TST)-positive prevalence (weighted prevalence = 6.4%) among 5476 children (<15 years) from 184 villages, with geographically isolated communities having prevalence as high as 29%. Therefore, we conducted a geospatial and hot spot analysis to examine the association between villages with high TST-positive prevalence (⩾6.5%) and access to medical care (distance (in kilometres and minutes of travel time) to the municipal Rural Health Units (RHU)), access to healthcare resources (distance to Provincial Health Office (PHO)) and socioeconomic determinants of health. Hot spot analysis revealed significant clusters of TST-positive prevalence in villages farthest from the PHO. Based on univariate analysis, the following variables associated with high prevalence were included in the multivariate model: minutes of travel time to the PHO, distance to the PHO, island villages and total deprivation based on socioeconomic indicators. In the final model, only distance to PHO in minutes was significant (P = 0.005). When evaluated further, greater than 1-hour drive significantly increased risk for TST-positivity (P = 0.003). Distance to healthcare resources likely increases the risk of TB transmission within the community. Expanding TB control efforts to geographically isolated areas is critical.
Recent studies have identified DAAO as a probable susceptibility gene for schizophrenia and bipolar disorder. However, little is known about how this gene may affect brain function to increase vulnerability to these disorders.
The present investigation examined the impact of DAAO genotype on brain function in patients with schizophrenia, patients with bipolar I disorder and healthy volunteers.
We tested the hypotheses that the high-risk variant of DAAO would be associated with altered prefrontal function and functional connectivity in schizophrenic and bipolar patients.
We used functional magnetic resonance imaging to measure brain responses during a verbal fluency task in a total of 121 subjects comprising 40 patients with schizophrenia, 33 patients with bipolar I disorder and 48 healthy volunteers. We then used statistical parametric mapping (SPM) and psycho-physiological interaction (PPI) analyses to estimate the main effects of diagnostic group, the main effect of genotype and their interaction on brain activation and functional connectivity.
In schizophrenic patients relative to bipolar patients and controls, the high-risk variant of DAAO was associated with lower deactivation in the left precuneus and greater activation in the right calcarine and posterior cingulate gyrus during task performance. In addiction, these areas expressed altered functional connectivity with the rest of the brain in schizophrenic patients relative to bipolar patients and controls.
Our results suggest that genetic variation in DAAO has a significant impact on brain function and provide preliminary evidence for a disease-specific pattern of gene action in specific brain regions.
P300 wave anomalies correlate with genetic risk for schizophrenia and constitute a plausible endophenotype for the disease. The COMT gene is thought to influence cognitive performance and to be a susceptibility gene for schizophrenia. Unlike two previous studies, we found no significant influence of the COMT gene on P300 amplitude or latency in 189 individuals examined. The well-supported role of the COMT gene both in dopamine catabolism as well as in prefrontal cognition makes a strong theoretical case for the influence of COMT Val158Met polymorphism on P300 endophenotypes. However, the available neurophysiologic evidence suggests that any such association, if present, must be very subtle.
It has long been known that cannabis can elicit an acute psychotic reaction. Recent work shows that, of the 60 cannabinoid molecules in the plant, delta-9-tetrahydrocannibinol is responsible for the central effects of cannabis. Here we aimed to investigate, in more detail, the psychological effects of synthetic intravenous THC in healthy subjects. Over 2 experimental sessions, participants (N=22) were administered 2.5mg IV THC or placebo under randomised, double-blind conditions. Psychological reactions were assessed using standard rating instruments and a battery of cognitive tests was completed.
Following THC, there was a significant increase in self-rated and observer-rated positive psychotic symptoms which were highly correlated (r=0.62, p=0.001).Phenomena centered on de-synchronisation of self-agency (ipseity disturbance) and hypersalience/paranoia. Participants also reported a significant increase in negative symptomatology under THC conditions, which was not explained by sedation. Finally, working memory/executive functioning was markedly and consistently impaired by THC.
Here we provide further evidence that THC can elicit an acute psychotic reaction in a proportion of healthy subjects. Acute THC-psychosis elicits positive, negative and cognitive symptoms. Compared with other drug models THC recreates symptomatology across 3 major dimensions of schizophrenic psychosis without sedation/clouding of consciousness. Here we also present preliminary evidence that the molecule cannabidiol (CBD) inhibits THC-elicited positive symptoms. Current work in our laboratory is exploring the underlying mechanisms.
Epidemiological studies have reported that the increased risk of developing psychosis in cannabis users is dose related. In addition, experimental research has shown that the active constituent of cannabis responsible for its psychotogenic effect is Delta-9-Tetrahydrocannabinol (THC) (Murray et al, 2007). Recent evidence has suggested an increased in potency (% TCH) in the cannabis seized in the UK (Potter et al, 2007).
We predicted that first episode psychosis patients are more likely to use higher potency cannabis and more frequently than controls.
We collected information concerning socio-demographic, clinical characteristics and cannabis use (age at first use, frequency, length of use, type of cannabis used) from a sample of 191 first-episode psychosis patients and 120 matched healthy volunteers. All were recruited as part of the Genetic and Psychosis (GAP) study which studied all patients who presented to the South London and Maudsley Trust.
There was no significant difference in the life-time prevalence of cannabis use or age at first use between cases and controls. However, cases were more likely to be regular users (p=0.05), to be current users (p=0.04) and to have smoked cannabis for longer (p=0.01). Among cannabis users, 86.8% of 1st Episode Psychosis Patients preferentially used Skunk/Sinsemilla compared to 27.7% of Controls. Only 13.2 % of 1st Episode psychosis Patients chose to use Resin/Hash compared to 76.3% of controls. The concentration of TCH in these in South East London, ranges between 8.5 and 14 % (Potter et al, 2007). Controls (47%) were more likely to use Hash (Resin) whose average TCH concentration is 3.4% (Potter et al, 2007).
Patients with first episode psychosis have smoked higher potency cannabis, for longer and with greater frequency, than healthy controls.
Junior doctors who trained in psychiatry at the Maudsley Hospital between 1965 to 1975 were followed up at a mean of 17 years to ascertain whether pre-psychiatric experience or performance during training could predict future career paths. The most consistent predictor of a career in academic psychiatry was involvement in research during training.
Prospective longitudinal investigations are needed to identify causal processes leading to schizophrenia. However, there is presently no cost-effective way to identify children who are at risk of developing schizophrenia spectrum disorders.
The present study tested the feasibility of screening community samples to identify children, aged 9-12 years, who experience a triad of putative antecedents of schizophrenia identified in previous research, including: (1) speech and/or motor development lags/problems; (2) social, emotional, or behavioural problems; and (3) psychotic-like-experiences. 3410 children and 796 caregivers completed questionnaires.
12.3% of boys and 8.0% of girls displayed the antecedent triad. Consistent with schizophrenia incidence data, children of African-Caribbean origin presented elevated risk for the antecedent triad relative to white British children. Preliminary results from event-related potential recordings in children presenting the triad (n=14; mean age: 11 years, 4 months; mean IQ: 111) and in control children experiencing none of the antecedents (n=9; mean age: 11 years, 6 months; mean IQ: 109), indicate brain function abnormalities in triad children. The amplitude of the error-related negativity (Ne/ERN) component elicited by erroneous responses to NoGo trials in a Go/NoGo task, relative to correct responses to Go trials, was reduced in children experiencing the triad (controlling for age and IQ). Similar reduction in Ne/ERN in adults with schizophrenia is thought to indicate deficits in patients’ internal monitoring of behaviour.
Questionnaire screening of community samples of children for the putative antecedents of schizophrenia is feasible. Accuracy of identification will be established only by follow-up studies.