829 results match your criteria: "Douglas Hospital Research Centre.[Affiliation]"

Cortical reactivation of spatial and non-spatial features coordinates with hippocampus to form a memory dialogue.

Nat Commun

November 2023

Canadian Centre for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, 4401 University Drive, Lethbridge, T1K 3M4, AB, Canada.

Episodic memories comprise diverse attributes of experience distributed across neocortical areas. The hippocampus is integral to rapidly binding these diffuse representations, as they occur, to be later reinstated. However, the nature of the information exchanged during this hippocampal-cortical dialogue remains poorly understood.

View Article and Find Full Text PDF

Sex differences in longitudinal changes of episodic memory-related brain activity and cognition in cognitively unimpaired older adults with a family history of Alzheimer's disease.

Neuroimage Clin

December 2023

Centre for Cerebral Imaging, Douglas Hospital Research Centre, Montreal, Quebec H4H 1R3, Canada; Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada; Department of Psychology, Toronto Metropolitan University, Toronto, Ontario M5B 2K3, Canada. Electronic address:

Episodic memory decline is an early symptom of Alzheimer's disease (AD) - a neurodegenerative disease that has a higher prevalence rate in older females compared to older males. However, little is known about why these sex differences in prevalence rate exist. In the current longitudinal task fMRI study, we explored whether there were sex differences in the patterns of memory decline and brain activity during object-location (spatial context) encoding and retrieval in a large sample of cognitively unimpaired older adults from the Pre-symptomatic Evaluation of Novel or Experimental Treatments for Alzheimer's Disease (PREVENT-AD) program who are at heightened risk of developing AD due to having a family history (+FH) of the disease.

View Article and Find Full Text PDF

Background: Early life adversity and psychiatric disorders are associated with earlier declines in neurocognitive abilities during adulthood. These declines may be preceded by changes in biological aging, specifically epigenetic age acceleration, providing an opportunity to uncover genome-wide biomarkers that identify individuals most likely to benefit from early screening and prevention.

Methods: Five unique epigenetic age acceleration clocks derived from peripheral blood were examined in relation to latent variables of general and speeded cognitive abilities across two independent cohorts: 1) the Female Growth and Development Study (FGDS;  = 86), a 30-year prospective cohort study of substantiated child sexual abuse and non-abused controls, and 2) the Biological Classification of Mental Disorders study (BeCOME;  = 313), an adult community cohort established based on psychiatric disorders.

View Article and Find Full Text PDF

Background: This study identified profiles associated with quality of life (QoL) and sociodemographic and clinical characteristics of patients using emergency departments (ED) for mental health reasons and associated these profiles with patient service use.

Methods: Recruited in four Quebec (Canada) ED networks, 299 patients with mental disorders (MD) were surveyed from March 1st, 2021, to May 13th, 2022. Data from medical records were collected and merged with survey data.

View Article and Find Full Text PDF

This longitudinal study identified profiles of patients with substance-related disorders (SRD) who did or did not drop out of specialized addiction treatment, integrating various patterns of outpatient service use. Medical administrative databases of Quebec (Canada) were used to investigate a cohort of 16,179 patients with SRD who received specialized addiction treatment. Latent class analysis identified patient profiles, based on multi-year outpatient service use.

View Article and Find Full Text PDF

Background: Genome-wide DNA methylation (DNAme) profiling of the placenta with Illumina Infinium Methylation bead arrays is often used to explore the connections between in utero exposures, placental pathology, and fetal development. However, many technical and biological factors can lead to signals of DNAme variation between samples and between cohorts, and understanding and accounting for these factors is essential to ensure meaningful and replicable data analysis. Recently, "epiphenotyping" approaches have been developed whereby DNAme data can be used to impute information about phenotypic variables such as gestational age, sex, cell composition, and ancestry.

View Article and Find Full Text PDF

Effectiveness of emergency department based interventions for frequent users with mental health issues: A systematic review.

Am J Emerg Med

December 2023

Division of Mental Health & Society, Douglas Hospital Research Centre, Montreal, Canada; Département de Gestion, Evaluation et Politique de Santé, Université de Montréal, Montréal, Canada; Department of Psychiatry, McGill University, Montreal, Canada. Electronic address:

Frequent emergency department (ED) users with mental health issues are particularly vulnerable patients, who often receive insufficient or inadequate outpatient care. This systematic review identified and evaluated studies on ED-based interventions to reduce acute care use by this population, while improving outpatient service use and patient outcomes. Searches were conducted in five databases for studies published between January 1, 2000, and April 30, 2022.

View Article and Find Full Text PDF

Time and experience are independent determinants of representational drift in CA1.

Neuron

August 2023

Department of Psychiatry, Faculty of Medicine, Douglas Hospital Research Centre, McGill University, Montreal, Canada; Integrated Program in Neuroscience, Faculty of Medicine, McGill University, Montreal, Canada. Electronic address:

In this issue of Neuron, Khatib et al. and Geva et al. present complementary and breakthrough discoveries demonstrating that elapsed time and active experience independently affect unique aspects of representational drift in the hippocampus.

View Article and Find Full Text PDF

Predictors of Physician Follow-Up Care Among Patients Affected by an Incident Mental Disorder Episode in Quebec (Canada).

Can J Psychiatry

February 2024

Centre de Recherche de l'Institut Universitaire en Santé Mentale de Montréal, Département de Psychiatrie, Université de Montréal, Montréal, QC, Canada.

Article Synopsis
  • * Data were analyzed from the Quebec Integrated Chronic Disease Surveillance System, covering a large cohort of over 2.6 million patients aged 12 and older, using various sociodemographic and clinical characteristics to determine predictors of follow-up care.
  • * Findings indicated that several groups, such as women and those with specific diagnoses or previous care experience, are more likely to receive follow-up care, while patients without prior mental health issues or those with certain disorders were less likely to engage in follow-up services.
View Article and Find Full Text PDF

Grid cell disruption in a mouse model of early Alzheimer's disease reflects reduced integration of self-motion cues.

Curr Biol

June 2023

Department of Psychiatry, Douglas Hospital Research Centre, McGill University, Montreal, QC H4H 1R3, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 0G4, Canada. Electronic address:

Converging evidence from human and rodent studies suggests that disrupted grid cell coding in the medial entorhinal cortex (MEC) underlies path integration behavioral deficits during early Alzheimer's disease (AD). However, grid cell firing relies on both self-motion cues and environmental features, and it remains unclear whether disrupted grid coding can account for specific path integration deficits reported during early AD. Here, we report in the J20 transgenic amyloid beta (Aβ) mouse model of early AD that grid cells were spatially unstable toward the center of the arena, had qualitatively different spatial components that aligned parallel to the borders of the environment, and exhibited impaired integration of distance traveled via reduced theta phase precession.

View Article and Find Full Text PDF

Introduction: Identifying determinants of emergency department (ED) use and hospitalization among patients with substance-related disorders (SRDs) can improve health services to address unmet health needs.

Aim: The present study aimed to identify the prevalence rates of ED use and hospitalization, and their associated determinants among patients with SRDs.

Methods: Studies in English published from January 1, 1995, to December 1, 2022, were searched on PubMed, Scopus, Cochrane Library, and Web of Science to identify primary studies.

View Article and Find Full Text PDF

Background: Pick's disease (PiD) is a rare and predominantly sporadic form of frontotemporal dementia that is classified as a primary tauopathy. PiD is pathologically defined by argyrophilic inclusion Pick bodies and ballooned neurons in the frontal and temporal brain lobes. PiD is characterised by the presence of Pick bodies which are formed from aggregated, hyperphosphorylated, 3-repeat tau proteins, encoded by the gene.

View Article and Find Full Text PDF

Cumulative effects of pre-pandemic vulnerabilities and pandemic-related hardship on psychological distress among pregnant individuals.

Gen Hosp Psychiatry

June 2023

Alberta Children's Hospital Research Institute (ACHRI), Calgary, Alberta, Canada; Department of Radiology, University of Calgary, Calgary, Alberta, Canada.

Objective: Our primary objective was to determine whether pre-existing vulnerabilities and resilience factors combined with objective hardship resulted in cumulative (i.e., additive) effects on psychological distress in pregnant individuals during the COVID-19 pandemic.

View Article and Find Full Text PDF

Objectives: This study investigated the use of outpatient care, and sociodemographic and clinical characteristics of patients with substance-related disorders (SRD) to predict treatment dropout from specialized addiction treatment centers. The study also explored risks of adverse outcomes, frequent emergency department (ED) use (3+ visits/year), and death, associated with treatment dropout within the subsequent 12 months.

Methods: The study examined a cohort of 16,179 patients who completed their last treatment episode for SRD between 2012-13 and 2014-15 (financial years: April 1 to March 31) in 14 specialized addiction treatment centers using Quebec (Canada) health administrative databases.

View Article and Find Full Text PDF

Reorientation, the process of regaining one's bearings after becoming lost, requires identification of a spatial context (context recognition) and recovery of heading direction within that context (heading retrieval). We previously showed that these processes rely on the use of features and geometry, respectively. Here, we examine reorientation behavior in a task that creates contextual ambiguity over a long timescale to demonstrate that mice learn to combine both featural and geometric cues to recover heading with experience.

View Article and Find Full Text PDF

Population dynamics of head-direction neurons during drift and reorientation.

Nature

March 2023

Department of Psychiatry, Douglas Hospital Research Centre, McGill University, Verdun, Quebec, Canada.

The head direction (HD) system functions as the brain's internal compass, classically formalized as a one-dimensional ring attractor network. In contrast to a globally consistent magnetic compass, the HD system does not have a universal reference frame. Instead, it anchors to local cues, maintaining a stable offset when cues rotate and drifting in the absence of referents.

View Article and Find Full Text PDF

Objective: To explore the housing trajectory, personal recovery, functional level, and quality of life of clients at discharge and 1 year after completing (PRISM), a shelter-based mental health and rehabilitation program intended to provide individuals experiencing homelessness and severe mental illness with transition housing and to reconnect them with mental health and social services.

Method: Housing status, psychiatric follow-up trajectory, personal recovery (Canadian Personal Recovery Outcome Measure), functional level (Multnomah Community Ability Scale), and quality of life (Lehman Quality of Life Interview) were assessed at program entry, at program discharge and 1 year later.

Results: Of the 50 clients who participated in the study from May 31, 2018, to December 31, 2019, 43 completed the program.

View Article and Find Full Text PDF

Background: Despite the existing knowledge about stress, trauma and pregnancy and maternal stress during natural disasters, little is known about what types of trauma pregnant or preconception women experience during these disasters. In May 2016, the worst natural disaster in modern Canadian history required the evacuation of nearly 90,000 residents of the Fort McMurray Wood Buffalo (FMWB) area of northern Alberta. Among the thousands of evacuees were an estimated 1850 women who were pregnant or soon to conceive.

View Article and Find Full Text PDF

The early caregiving environment can have lasting effects on child mental health. Animal models suggest that glucocorticoid receptor gene () DNA methylation plays a mediating role in linking more responsive caregiving to improved behavioral outcomes by its impact on the stress regulatory system. In this longitudinal study, we examined whether children's methylation levels mediate an effect of maternal sensitivity in infancy on levels of child internalizing and externalizing behavior in a community sample.

View Article and Find Full Text PDF

Profiles, correlates, and risk of death among patients with mental disorders hospitalized for psychiatric reasons.

Psychiatry Res

March 2023

Département de Psychiatrie et d'Addictologie, Université de Montréal, 2900 Boulevard Édouard-Montpetit, Montreal, Quebec H3T 1J4, Canada; Centre de Recherche Fernand-Seguin, Institut Universitaire en Santé Mentale de Montréal, 7401 Rue Hochelaga, Montreal, Quebec H1N 3V2, Canada.

This study identified profiles of hospitalized patients with mental disorders (MD) based on their 3-year hospitalization patterns and clinical characteristics and compared sociodemographic profiles and other service use correlates as well as risk of death within 12 months after hospitalization. Quebec (Canada) medical administrative databases were used to investigate a 5-year cohort of 4,400 patients hospitalized for psychiatric reasons. Latent class analysis, chi-square tests and survival analysis were produced.

View Article and Find Full Text PDF

Human brain development starts in the embryonic period. Maternal preconception nutrition and nutrient availability to the embryo may influence brain development at this critical period following conception and early cellular differentiation, thereby affecting offspring neurodevelopmental and behavioural disorder risk. However, studying this is challenging due to difficulties in characterizing preconception nutritional status and few studies have objective neurodevelopmental imaging measures in children.

View Article and Find Full Text PDF

Background: This study identified patient profiles in terms of their quality of outpatient care use, associated sociodemographic and clinical characteristics, and adverse outcomes based on frequent emergency department (ED) use, hospitalization, and death from medical causes.

Methods: A cohort of 18,215 patients with substance-related disorders (SRD) recruited in addiction treatment centers was investigated using Quebec (Canada) health administrative databases. A latent class analysis was produced, identifying three profiles of quality of outpatient care use, while multinomial and logistic regressions tested associations with patient characteristics and adverse outcomes, respectively.

View Article and Find Full Text PDF

Genetic studies in humans have implicated the gene encoding neuregulin-1 (NRG-1) as a candidate susceptibility gene for schizophrenia. Furthermore, it has been suggested that NRG-1 is involved in regulating the expression and function of the -methyl-D-aspartate receptor and the GABA receptor in several brain areas, including the prefrontal cortex (PFC), the hippocampus, and the cerebellum. Neonatal ventral hippocampal lesioned (NVHL) rats have been considered as a putative model for schizophrenia with characteristic post-pubertal alteration in response to stress and neuroleptics.

View Article and Find Full Text PDF

Identifying the determinants of emergency department (ED) use and hospitalization among patients with substance-related disorders (SRD) can help inform healthcare services and case management regarding their unmet health needs and strategies to reduce their acute care. The present study aimed to identify sociodemographic characteristics, type of used drug, and risky behaviors associated with ED use and hospitalization among patients with SRD. : Studies in English published from January 1st, 1995 to April 30th, 2022 were searched from and to identify primary studies on ED use and hospitalization among patients with SRD.

View Article and Find Full Text PDF