Montréal, Canada
Montréal, Canada

Time filter

Source Type

Thompson W.K.,Psychiatry | Holland D.,University of California at San Diego | Rddey J.C.,University of California at San Diego | Blennow K.,Goteburg University | And 4 more authors.
Annals of Neurology | Year: 2011

The relationship between neurodegeneration and the 2 hallmark proteins of Alzheimer's disease, amyloid-b (Ab) and tau, is still unclear. Here, we examined 286 nondemented participants (107 cognitively normal older adults and 179 memory impaired individuals) who underwent longitudinal magnetic resonance (MR) imaging and lumbar puncture. Using mixed effects models, we investigated the relationship between longitudinal entorhinal cortex atrophy rate, cerebrospinal fluid (CSF) p-tau181p and CSF Ab1-42. We found a significant relationship between elevated entorhinal cortex atrophy rate and decreased CSF Ab1-42 only with elevated CSF ptau181p. Our findings indicate that Ab-associated volume loss occurs only in the presence of phospho-tau in humans at risk for dementia. © 2011 American Neurological Association.


PubMed | Psychiatry
Type: Journal Article | Journal: JMIR mHealth and uHealth | Year: 2017

Evaluating engagement with an intervention is a key component of understanding its efficacy. With an increasing interest in developing behavioral interventions in the mobile health (mHealth) space, appropriate methods for evaluating engagement in this context are necessary. Data collected to evaluate mHealth interventions are often collected much more frequently than those for clinic-based interventions. Additionally, missing data on engagement is closely linked to level of engagement resulting in the potential for informative missingness. Thus, models that can accommodate intensively collected data and can account for informative missingness are required for unbiased inference when analyzing engagement with an mHealth intervention.The objectives of this paper are to discuss the utility of the joint modeling approach in the analysis of longitudinal engagement data in mHealth research and to illustrate the application of this approach using data from an mHealth intervention designed to support illness management among people with schizophrenia.Engagement data from an evaluation of an mHealth intervention designed to support illness management among people with schizophrenia is analyzed. A joint model is applied to the longitudinal engagement outcome and time-to-dropout to allow unbiased inference on the engagement outcome. Results are compared to a nave model that does not account for the relationship between dropout and engagement.The joint model shows a strong relationship between engagement and reduced risk of dropout. Using the mHealth app 1 day more per week was associated with a 23% decreased risk of dropout (P<.001). The decline in engagement over time was steeper when the joint model was used in comparison with the nave model.Nave longitudinal models that do not account for informative missingness in mHealth data may produce biased results. Joint models provide a way to model intensively collected engagement outcomes while simultaneously accounting for the relationship between engagement and missing data in mHealth intervention research.


Bagcioglu E.,Afyonkocatepe University | Isikli H.,Psychiatry | Demirel H.,Forensic Medical Council | Sahin E.,Forensic Medical Council | And 4 more authors.
Comprehensive Psychiatry | Year: 2014

Objective We aimed to investigate facial emotion recognition abilities in violent individuals with antisocial personality disorder who have comorbid attention deficient hyperactivity disorder (ADHD) or not. Method The photos of happy, surprised, fearful, sad, angry, disgust, and neutral facial expressions and Wender Utah Rating Scale have been performed in all groups. Results The mean ages were as follows: in antisocial personality disorder with ADHD 22.0 ± 1.59, in pure antisocial individuals 21.90 ± 1.80 and in controls 22.97 ± 2.85 (p > 0.05). The mean score in Wender Utah Rating Scale was significantly different between groups (p < 0.001). The mean accurate responses to each facial emotion between groups were insignificant (p > 0.05) excluding disgust faces which was significantly impaired in ASPD + ADHD and pure ASPD groups. Antisocial individuals with attention deficient and hyperactivity had spent significantly more time to each facial emotion than healthy controls (p < 0.05) while pure antisocial individual had more time to recognize disgust and neutral faces than healthy controls (p < 0.05). Conclusion Study of complex social cognitive abilities in adults with ADHD and violent behaviors is lacking. This study is the first, investigating the differences according to social cognition cues in violent individual that revealed no significance within pure antisocial individuals and antisocial individuals with ADHD. © 2014 Elsevier Inc.


Garfinkel S.N.,Psychiatry | Garfinkel S.N.,Sackler Center for Consciousness Science | Manassei M.F.,Brighton and Sussex Medical School | Hamilton-Fletcher G.,University of Sussex | And 5 more authors.
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016

Interoception refers to the sensing of signals concerning the internal state of the body. Individual differences in interoceptive sensitivity are proposed to account for differences in affective processing, including the expression of anxiety. The majority of investigations of interoceptive accuracy focus on cardiac signals, typically using heartbeat detection tests and self-report measures. Consequently, little is known about how different organ-specific axes of interoception relate to each other or to symptoms of anxiety. Here, we compare interoception for cardiac and respiratory signals. We demonstrate a dissociation between cardiac and respiratory measures of interoceptive accuracy (i.e. task performance), yet a positive relationship between cardiac and respiratory measures of interoceptive awareness (i.e. metacognitive insight into own interoceptive ability). Neither interoceptive accuracy nor metacognitive awareness for cardiac and respiratory measures was related to touch acuity, an exteroceptive sense. Specific measures of interoception were found to be predictive of anxiety symptoms. Poor respiratory accuracy was associated with heightened anxiety score, while good metacognitive awareness for cardiac interoception was associated with reduced anxiety. These findings highlight that detection accuracies across different sensory modalities are dissociable and future work can better delineate their relationship to affective and cognitive constructs. This article is part of the themed issue ‘Interoception beyond homeostasis: affect, cognition and mental health’. © 2016 The Author(s) Published by the Royal Society. All rights reserved.


Garfinkel S.N.,Psychiatry | Garfinkel S.N.,University of Sussex | Seth A.K.,University of Sussex | Barrett A.B.,University of Sussex | And 3 more authors.
Biological Psychology | Year: 2015

Interoception refers to the sensing of internal bodily changes. Interoception interacts with cognition and emotion, making measurement of individual differences in interoceptive ability broadly relevant to neuropsychology. However, inconsistency in how interoception is defined and quantified led to a three-dimensional model. Here, we provide empirical support for dissociation between dimensions of: (1) interoceptive accuracy (performance on objective behavioural tests of heartbeat detection), (2) interoceptive sensibility (self-evaluated assessment of subjective interoception, gauged using interviews/questionnaires) and (3) interoceptive awareness (metacognitive awareness of interoceptive accuracy, e.g. confidence-accuracy correspondence). In a normative sample (. N=. 80), all three dimensions were distinct and dissociable. Interoceptive accuracy was only partly predicted by interoceptive awareness and interoceptive sensibility. Significant correspondence between dimensions emerged only within the sub-group of individuals with greatest interoceptive accuracy. These findings set the context for defining how the relative balance of accuracy, sensibility and awareness dimensions explain cognitive, emotional and clinical associations of interoceptive ability. © 2014 The Authors.


PubMed | Psychiatry, Brighton and Sussex Medical School, University of Sussex and Maastricht University
Type: Journal Article | Journal: Philosophical transactions of the Royal Society of London. Series B, Biological sciences | Year: 2017

Interoception refers to the sensing of signals concerning the internal state of the body. Individual differences in interoceptive sensitivity are proposed to account for differences in affective processing, including the expression of anxiety. The majority of investigations of interoceptive accuracy focus on cardiac signals, typically using heartbeat detection tests and self-report measures. Consequently, little is known about how different organ-specific axes of interoception relate to each other or to symptoms of anxiety. Here, we compare interoception for cardiac and respiratory signals. We demonstrate a dissociation between cardiac and respiratory measures of interoceptive accuracy (i.e. task performance), yet a positive relationship between cardiac and respiratory measures of interoceptive awareness (i.e. metacognitive insight into own interoceptive ability). Neither interoceptive accuracy nor metacognitive awareness for cardiac and respiratory measures was related to touch acuity, an exteroceptive sense. Specific measures of interoception were found to be predictive of anxiety symptoms. Poor respiratory accuracy was associated with heightened anxiety score, while good metacognitive awareness for cardiac interoception was associated with reduced anxiety. These findings highlight that detection accuracies across different sensory modalities are dissociable and future work can better delineate their relationship to affective and cognitive constructs.This article is part of the themed issue Interoception beyond homeostasis: affect, cognition and mental health.


Bagley S.C.,Psychiatry
Suicide & life-threatening behavior | Year: 2010

Military personnel and veterans have important suicide risk factors. After a systematic review of the literature on suicide prevention, seven (five in the U.S.) studies of military personnel were identified containing interventions that may reduce the risk of suicide. The effectiveness of the individual components was not assessed, and problems in methodology or reporting of data were common. Overall, multifaceted interventions for active duty military personnel are supported by consistent evidence, although of very mixed quality, and in some cases during intervals of declines in suicide rates in the general population. There were insufficient studies of U.S. Veterans to reach conclusions.


Greif R.,Psychiatry | Becker C.B.,Trinity University | Hildebrandt T.,Psychiatry
International Journal of Eating Disorders | Year: 2015

Objective Impediments limit dissemination and implementation of evidence-based interventions (EBIs), including lack of sufficient training. One strategy to increase implementation of EBIs is the train-the-trainer (TTT) model. The Body Project is a peer-led body image program that reduces eating disorder (ED) risk factors. This study examined the effectiveness of a TTT model at reducing risk factors in Body Project participants. Specifically, this study examined whether a master trainer could train a novice trainer to train undergraduate peer leaders to administer the Body Project such that individuals who received the Body Project (i.e., participants) would evidence comparable outcomes to previous trials. We hypothesized that participants would evidence reductions in ED risk factors, with effect sizes similar to previous trials. Method Utilizing a TTT model, a master trainer trained a novice trainer to train undergraduate peer leaders to administer the Body Project to undergraduate women. Undergraduate women aged 18 years or older who received the Body Project intervention participated in the trial and completed measures at baseline, post-treatment, and five-month follow-up. Primary outcomes included body dissatisfaction, thin ideal internalization, negative affect, and ED pathology. Results Participants demonstrated significant reductions in thin ideal internalization, ED pathology and body dissatisfaction at post-treatment and 5-month follow-up. At 5 months, using three different strategies for managing missing data, effect sizes were larger or comparable to earlier trials for 3 out of 4 variables. Discussion Results support a TTT model for Body Project implementation and the importance of utilizing sensitivity analyses for longitudinal datasets with missing data. © 2015 Wiley Periodicals, Inc.


Quera-Salva M.-A.,Raymond Poincare Hospital | Lemoine P.,Psychiatry | Guilleminault C.,Stanford University
Human Psychopharmacology | Year: 2010

Background: Disturbance of sleep-wake cycles is common in major depressive disorder (MDD), usually as insomnia, but also as hypersomnia or reduced daytime alertness. Agomelatine, an MT1 and MT2 receptor agonist and 5-HT2C receptor antagonist, represents a novel approach in MDD, with proven antidepressant efficacy and a positive impact on the sleep-wake cycle. We review the effects of agomelatine 25/50 mg/day on objective and subjective measures of the sleep-wake cycle in MDD. Subjective measures: Agomelatine improved all aspects of the sleep-wake cycle from as early as 1 week in randomized trials versus selective serotonin reuptake inhibitors and venlafaxine, particularly getting off to sleep and quality of sleep, with an improvement in daytime alertness. Objective measures: Agomelatine's effect on sleep architecture in MDD has been measured by polysomnography (PSG). There were significant improvements in sleep efficiency, slow-wave sleep (SWS), and the distribution of delta activity throughout the night, but no change in amount or latency of rapid eye movement (REM) sleep. Furthermore, the slow-wave sleep was resynchronized to the first sleep cycle of the night. Conclusion: Agomelatine, a novel antidepressant, improves disturbed sleep-wake cycles in MDD. The improvement of both nighttime sleep and daytime functioning with agomelatine are promising features of this antidepressant regarding the management of MDD. Copyright © 2010 John Wiley & Sons, Ltd.


Berman M.I.,Psychiatry | Hegel M.T.,Psychiatry
Psychotherapy Research | Year: 2014

Objective: Recursive partitioning was applied to a longitudinal dataset of outpatient mental health clinic patients to identify empirically factors and interactions among factors that best predicted clinical improvement and deterioration in symptoms of depression across treatment. Method: Sixty-two variables drawn from an initial patient survey and from chart review were included as covariates in the analysis, representing nearly all of the demographic, treatment, symptom, diagnostic, and social history information obtained from patients at their initial evaluations. Trees estimated the probability of participants' having depression at their last assessment, improving to a clinically significant degree during treatment, or developing a new onset of significant depressive symptoms during treatment. Results: Initial pain, the presence of anxiety, and a history of multiple types of abuse were risk factors for poorer outcome, even among patients who did not initially have significant depressive symptoms. Conclusions: By examining multiple-related outcomes, we were able to create a series of overlapping models that revealed important predictors across trees. Limitations of the study included the lack of cross-validation of the trees and the exploratory nature of the analysis. © 2014, Society for Psychotherapy Research.

Loading Psychiatry collaborators
Loading Psychiatry collaborators