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BACKGROUND Individuals with an "At Risk Mental State" have a 20-30% chance of developing a psychotic disorder within two years; however it is difficult to predict which individuals will become ill on the basis of their clinical symptoms alone. We examined whether mismatch negativity (MMN) could help to identify those who are particularly likely to make a(More)
BACKGROUND Major depressive disorder (MDD) is a common mental illness with high lifetime prevalence close to 20%. Positron emission tomography (PET) studies have reported decreased prefrontal, insular and limbic cerebral glucose metabolism in depressed patients compared with healthy controls. However, the literature has not always been consistent. To(More)
BACKGROUND Morphometric endophenotypes which have been proposed for psychotic disorders include lateral ventricular enlargement and hippocampal volume reductions. Genetic epidemiological studies support an overlap between schizophrenia and bipolar disorder, and COMT, BDNF, 5-HTT, NRG1 and DTNBP1 genes have been implicated in the aetiology of both these(More)
INTRODUCTION Abnormalities in the neurophysiological measures P300 amplitude and latency constitute endophenotypes for psychosis. Disrupted-in-Schizophrenia-1 (DISC1) has been proposed as a promising susceptibility gene for schizophrenia, and a previous study has suggested that it is associated with P300 deficits in schizophrenia. METHODS We examined the(More)
INTRODUCTION Abnormalities of the P300 event related potential (ERP) and of hippocampal structure are observed in individuals with psychotic disorders and their unaffected relatives. The understanding and clinical management of psychotic disorders are largely based on the descriptive Kraepelinian distinction between 'dementia praecox' and 'manic depressive(More)
BACKGROUND Finding reliable endophenotypes for psychosis could lead to an improved understanding of aetiology, and provide useful alternative phenotypes for genetic association studies. Resting quantitative electroencephalography (QEEG) activity has been shown to be heritable and reliable over time. However, QEEG research in patients with psychosis has(More)
BACKGROUND Auditory P50 sensory gating deficits correlate with genetic risk for schizophrenia and constitute a plausible endophenotype for the disease. The well-supported role of catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF) and neuregulin 1 (NRG1) genes in neurodevelopment and cognition make a strong theoretical case for(More)
Schizophrenia is often regarded as a "dysconnectivity" disorder and recent work using graph theory has been used to better characterize dysconnectivity of the structural connectome in schizophrenia. However, there are still little data on the topology of connectomes in less severe forms of the condition. Such analysis will identify topological markers of(More)
Individuals at clinical high risk (CHR) of developing psychosis present with widespread functional abnormalities in the brain. Cognitive deficits, including working memory (WM) problems, as commonly elicited by n-back tasks, are observed in CHR individuals. However, functional MRI (fMRI) studies, comprising a heterogeneous cluster of general and social(More)
The mismatch negativity (MMN) evoked potential, a preattentive brain response to a discriminable change in auditory stimulation, is significantly reduced in psychosis. Glutamatergic theories of psychosis propose that hypofunction of NMDA receptors (on pyramidal cells and inhibitory interneurons) causes a loss of synaptic gain control. We measured changes in(More)