Search results for "PSYCHOSIS"
showing 10 items of 324 documents
Prevalence of bullying victimisation amongst first-episode psychosis patients and unaffected controls
2013
Background—Despite increasing evidence suggesting that childhood maltreatment is significantly associated with psychosis, the specific role of bullying in the onset of psychotic disorders is still unclear. This study aimed to examine whether bullying was more prevalent amongst individuals presenting to services for the first time with a psychotic disorder than in unaffected community controls. Methods—Data on exposure to bullying, psychotic symptoms, cannabis use and history of conduct disorder were collected cross-sectionally from 222 first-presentation psychosis cases and 215 geographically-matched controls. Bullying victimisation was assessed retrospectively as part of the Brief Life Eve…
Association Study of Nonsynonymous Single Nucleotide Polymorphisms in Schizophrenia
2010
Genome-wide association studies using several hundred thousand anonymous markers present limited statistical power. Alternatively, association studies restricted to common nonsynonymous single nucleotide polymorphisms (nsSNPs) have the advantage of strongly reducing the multiple testing problem, while increasing the probability of testing functional single nucleotide polymorphisms (SNPs).We performed a case-control association study of common nsSNPs in Galician (northwest Spain) samples using the Affymetrix GeneChip Human 20k cSNP Kit, followed by a replication study of the more promising results. After quality control procedures, the discovery sample consisted of 5100 nsSNPs at minor allel…
Gene-environment interaction as a predictor of early adjustment in first episode psychosis.
2017
Abstract Background This study aims to explore the gene-environment interaction hypothesis applied to pre-symptomatic neurodevelopmental phenotypes of first episode psychosis (FEP), that is, genetic factors might increase vulnerability to the effects of environmental adverse conditions occurring at later stages of development. Methods We constructed a schematic ‘two-hit’ model, with Val/Val homozygosity for the catechol- O -methyltransferase ( COMT ) Val158Met polymorphism as the ‘first hit’ and history of obstetric complications and parental socioeconomic status as ‘second hits’. Early adjustment, measured using the Premorbid Adjustment Scale, was considered the main outcome. The study pop…
Neuropsychological indicators of the vulnerability to schizophrenia
1992
Schizophrenia is associated with enduring deficits in neuropsychological functioning. It is widely undecided if the various aspects of neuropsychological impairment are a consequence of the disorder or if they are also present premorbidly and in populations at increased risk for schizophrenia (vulnerability markers). Neuropsychological deficits in healthy relatives of schizophrenic patients who are at an elevated risk for schizophrenia and who did not yet pass the period of risk would indicate that these deficits are vulnerability markers. This hypothesis was tested for three neuropsychological paradigms which have been proven to distinguish schizophrenic patients from controls. 33 siblings…
Straight gyrus morphology in first-episode schizophrenia-spectrum patients
2010
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The structure and correlates of self-injurious behavior in an institutional setting
2001
The prevalence of self-injurious behavior (SIB) in an institution for people with mental retardation was investigated. The relationship between SIB and age, sex, level of retardation, length of institutionalization, adaptive behavior, and probable causes of mental retardation was examined. A factor analysis on the topographies of SIB indicated the existence of two forms of SIB, stereotyped and social. The results are discussed in terms of probable causes of SIB.
Reduced oscillatory gamma-band responses in unmedicated schizophrenic patients indicate impaired frontal network processing
2004
Abstract Objective Integration of sensory information by cortical network binding appears to be crucially involved in target detection. Studies in schizophrenia using functional and diffusion tensor neuroimaging, event-related potentials and EEG coherence indicate an impairment of cortical network coupling in this disorder. Previous electrophysiological investigations in animals and humans suggested that gamma activity (oscillations at around 40 Hz) is essential for cortical network binding. Studies in medicated schizophrenia provide evidence for a reduced gamma activity in the context of auditory stimulus processing. This is the first investigation of oscillatory activations in the gamma-b…
Predictors of neurocognitive impairment at 3years after a first episode non-affective psychosis
2013
Abstract Background Neurocognitive impairment is a core component of schizophrenia. However, patients show great variability in the level and course of deficits. The goal of the present longitudinal study was to identify predictors of neurocognitive impairment in first episode psychosis patients. Methods N eurocognitive performance was analyzed in a cohort of 146 patients 3 years after a first episode non-affective psychosis. Subgroups, impaired vs. unimpaired, were compared on baseline clinical, neuropsychological, premorbid and sociodemographic characteristics. Results Fifty-nine percent of participants presented general neurocognitive impairment and regression analyses demonstrated that …
A replication study on P300 single trial analysis in schizophrenia: confirmation of a reduced number of 'true positive' P300 waves.
2000
A single trial analysis of event-related potentials (auditory odd-ball paradigm) of 20 schizophrenics was performed in comparison to matched healthy controls. The purpose of the study was to test the hypothesis that in schizophrenia the well-known P300 amplitude reduction of averaged event-related potentials is due to fewer elicited single trial P300 waves. The results of the present study support this finding of our previous exploratory investigation and point to the view that schizophrenics reveal basal disturbances in information processing due to inadequately elicited electrophysiological responses to target stimuli.
Variations in genes regulating neuronal migration predict reduced prefrontal cognition in schizophrenia and bipolar subjects from mediterranean Spain…
2005
Both neural development and prefrontal cortex function are known to be abnormal in schizophrenia and bipolar disorder. In order to test the hypothesis that these features may be related with genes that regulate neuronal migration, we analyzed two genomic regions: the lissencephaly critical region (chromosome 17p) encompassing the LIS1 gene and which is involved in human lissencephaly; and the genes related to the platelet-activating-factor, functionally related to LIS1, in 52 schizophrenic patients, 36 bipolar I patients and 65 normal control subjects. In addition, all patients and the 25 control subjects completed a neuropsychological battery. Thirteen (14.8%) patients showed genetic varia…