Publications by authors named "Peter Zachar"

Work at the intersection of philosophy and psychiatry has an extensive and influential history, and has received increased attention recently, with the emergence of professional associations and a growing literature. In this paper, we review key advances in work on philosophy and psychiatry, and their related clinical implications. First, in understanding and categorizing mental disorder, both naturalist and normativist considerations are now viewed as important - psychiatric constructs necessitate a consideration of both facts and values.

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This article extends the ideas expressed in a special section on theories of psychopathology by expounding on heterotypic patterns in which different arrangements of symptoms appear over time. With heterotypic continuity, the different arrangements are somewhat predictable; with discontinuity, they are not. Among the reasons the articles in the special section give for heterotypic patterns are the lack of central controllers for producing symptom clusters, the importance of transdiagnostic factors, and the dynamics of gene-environment correlations.

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In the early 1990s, a research group that included Holly Prigerson and Charles Reynolds established that disordered grief overlaps with depression and anxiety but is not the same. They also developed a research inventory for studying disordered grief. Subsequently, Prigerson focused on measuring disordered grief using advanced psychometric techniques.

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Objective: This article narrates a history of several important changes to the substance-related disorders chapter in the (DSM-5), based on interviews with people involved in the pre-planning and the development of the revisions. These changes include collapsing substance abuse and substance dependence into a single substance use disorder, adding craving as a diagnostic criterion, and incorporating a behavioral addiction--gambling disorder--into the substance-related disorders chapter. Studies using Item Response Theory (IRT) supported the new substance use disorder diagnosis.

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This article narrates a consensus history of the proposal to include diagnostic criteria for a psychosis risk syndrome in the DSM-5, in part, to document what happened, but also to potentially help focus future efforts at clinically useful early detection. The purpose of diagnosing a risk state would be to slow and ideally prevent the development of the full disorder. Concerns about diagnosing a psychosis risk state included a high false positive rate, potentially harmful use of anti-psychotic medication with people who would not transition to psychosis, and stigmatization.

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The initial plans for the DSM-5 revision envisioned a paradigm shift away from traditional diagnostic categories. However, plans for a major move from descriptive to etiologic diagnoses were quickly abandoned as infeasible. Support was much broader for adding dimensional/spectrum constructs to the categorical diagnoses, although this was interpreted in various ways.

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We have developed a renewable, scalable and transgene free human blood-brain barrier model, composed of brain endothelial cells (BECs), generated from human amniotic fluid derived induced pluripotent stem cells (AF-iPSC), which can also give rise to syngeneic neural cells of the neurovascular unit. These AF-iPSC-derived BECs (i-BEC) exhibited high transendothelial electrical resistance (up to 1500 Ω cm) inducible by astrocyte-derived molecular cues and retinoic acid treatment, polarized expression of functional efflux transporters and receptor mediated transcytosis triggered by antibodies against specific receptors. In vitro human BBB models enable pre-clinical screening of central nervous system (CNS)-targeting drugs and are of particular importance for assessing species-specific/selective transport mechanisms.

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The neuroepithelial cell (NEC) of the fish gill is an important model for O sensing in vertebrates; however, a complete picture of the chemosensory mechanisms in NECs is lacking, and O chemoreception in vertebrates that are tolerant to anoxia has not yet been explored. Using whole cell patch-clamp recording, we characterized four types of ion channels in NECs isolated from the anoxia-tolerant goldfish. A Ca-dependent K current () peaked at ~20 mV, was potentiated by increased intracellular Ca, and was reduced by 100 μM Cd A voltage-dependent inward current in Ba solution, with peak at 0 mV, confirmed the presence of Ca channels.

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Many scholars believe that psychiatric nosology is undergoing a crisis of confidence. Some of the issues up for debate hark back to the introduction of the natural history approach to classification in the seventeenth century. Natural histories map sameness and difference rather than speculate about causes.

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Acetylcholine is an excitatory neurotransmitter important for oxygen sensing in mammals. A cholinergic mechanism in the fish gill has been implicated in the hyperventilatory response to acute hypoxia; however, the identity and distribution of acetylcholine-containing cells in the gills is poorly defined. We test the hypothesis that cholinergic cells are present in the gill filament epithelium in zebrafish (Danio rerio), a model vertebrate for which oxygen chemoreceptors are well characterized, and that these cells would receive nervous innervation.

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Purpose Of Review: To propose options for gradually transitioning to a thoroughgoing dimensional model of personality disorder.

Recent Findings: The American Psychiatric Association was less willing to implement a dimensional approach to the diagnosis of personality disorder than the leadership of the DSM-5 anticipated. The next opportunity to implement such an approach will be in the ICD-11 and the DSM 5.

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The story of control of cardiorespiratory reflexes by peripheral chemoreceptors includes a chapter on evolution in large part because of the work of Prof. William K. Milsom.

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The proposals to include a menstruation-related mood disorder in the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R), and DSM-IV led to intense public and behind-the-scenes controversy. Although the controversies surrounding the DSM-5 revision were greater in number than the controversies of the earlier revisions, the DSM-5 proposal to include a menstruation-related mood disorder was not among them. Premenstrual dysphoric disorder was made an official disorder in the DSM-5 with no significant protest.

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About 17% of humanity goes through an episode of major depression at some point in their lifetime. Despite the enormous societal costs of this incapacitating disorder, it is largely unknown how the likelihood of falling into a depressive episode can be assessed. Here, we show for a large group of healthy individuals and patients that the probability of an upcoming shift between a depressed and a normal state is related to elevated temporal autocorrelation, variance, and correlation between emotions in fluctuations of autorecorded emotions.

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In the conclusion to this multi-part article I first review the discussions carried out around the six essential questions in psychiatric diagnosis - the position taken by Allen Frances on each question, the commentaries on the respective question along with Frances' responses to the commentaries, and my own view of the multiple discussions. In this review I emphasize that the core question is the first - what is the nature of psychiatric illness - and that in some manner all further questions follow from the first. Following this review I attempt to move the discussion forward, addressing the first question from the perspectives of natural kind analysis and complexity analysis.

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The chemosensory roles of gill neuroepithelial cells (NECs) in mediating the hyperventilatory response to hypoxia are not clearly defined in fish. While serotonin (5-HT) is the predominant neurotransmitter in O(2)-sensitive gill NECs, acetylcholine (ACh) plays a more prominent role in O(2) sensing in terrestrial vertebrates. The present study characterized the developmental chronology of potential serotonergic and cholinergic chemosensory pathways of the gill in the model vertebrate, the zebrafish (Danio rerio).

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In the zebrafish, O(2)-chemoreceptive neuroepithelial cells (NECs) of the gill arches detect changes in PO(2) and are believed to initiate cardiorespiratory responses to hypoxia. Goldfish have gill NECs of similar morphology and innervation, yet these animals are naturally tolerant to prolonged periods of anoxia. Whole-cell, voltage-clamp experiments indicated that goldfish NECs express a variety of membrane ion channels, including background and Ca(2+)-activated K(+) channels.

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A highly sensitive oxygen (O(2)) sensing mechanism is critical for the survival of all vertebrate species. In fish, this requirement is fullfilled by the neuroepithelial cells (NECs) of the gill. NECs are neurotransmitter-containing chemosensory cells that are diffusely distributed within a thin epithelial layer of the filaments and respiratory lamellae of all gill arches, and are innervated by afferent fibers from the central nervous system.

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In face of the multiple controversies surrounding the DSM process in general and the development of DSM-5 in particular, we have organized a discussion around what we consider six essential questions in further work on the DSM. The six questions involve: 1) the nature of a mental disorder; 2) the definition of mental disorder; 3) the issue of whether, in the current state of psychiatric science, DSM-5 should assume a cautious, conservative posture or an assertive, transformative posture; 4) the role of pragmatic considerations in the construction of DSM-5; 5) the issue of utility of the DSM - whether DSM-III and IV have been designed more for clinicians or researchers, and how this conflict should be dealt with in the new manual; and 6) the possibility and advisability, given all the problems with DSM-III and IV, of designing a different diagnostic system. Part 1 of this article took up the first two questions.

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In face of the multiple controversies surrounding the DSM process in general and the development of DSM-5 in particular, we have organized a discussion around what we consider six essential questions in further work on the DSM. The six questions involve: 1) the nature of a mental disorder; 2) the definition of mental disorder; 3) the issue of whether, in the current state of psychiatric science, DSM-5 should assume a cautious, conservative posture or an assertive, transformative posture; 4) the role of pragmatic considerations in the construction of DSM-5; 5) the issue of utility of the DSM--whether DSM-III and IV have been designed more for clinicians or researchers, and how this conflict should be dealt with in the new manual; and 6) the possibility and advisability, given all the problems with DSM-III and IV, of designing a different diagnostic system. Part I of this article took up the first two questions.

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