Jennifer H. Barnett

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The catechol-O-methyltransferase (COMT) Val(158)Met polymorphism is hypothesized to affect executive function in patient and control populations. Studies inconsistently report better performance on the Wisconsin Card Sort Test (WCST) in individuals with one or more Met alleles. We conducted a meta-analysis of studies published until August 2006 that(More)
BACKGROUND Cognitive endophenotypes may further our understanding of the genetic basis of psychiatric disorders, and the catechol-O-methyltransferase (COMT) gene is a promising candidate gene for both cognitive function and disorder. We conducted a meta-analysis of reported associations between the COMT Val158/108Met polymorphism and measures of memory and(More)
Cognitive dysfunction in schizophrenia is an important target for novel therapies. Effectively measuring the cognitive effects of compounds in clinical trials of schizophrenia could be a major barrier to drug development. The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) programme produced a consensus cognitive battery(More)
OBJECTIVE A premorbid IQ deficit supports a developmental dimension to schizophrenia and its cognitive aspects that are crucial to functional outcome. Better characterisation of the association between premorbid IQ and the disorder may provide further insight into its origin and etiology. We aimed to quantify premorbid cognitive function in schizophrenia(More)
BACKGROUND Some personality characteristics have previously been associated with an increased risk for psychiatric disorder. Longitudinal studies are required in order to tease apart temporary (state) and enduring (trait) differences in personality among individuals with bipolar disorder (BD). This study aimed to determine whether there is a characteristic(More)
BACKGROUND Substance use is implicated in the cause and course of psychosis. AIMS To characterise substance and alcohol use in an epidemiologically representative treatment sample of people experiencing a first psychotic episode in south Cambridgeshire. METHOD Current and lifetime substance use was recorded for 123 consecutive referrals to a specialist(More)
OBJECTIVE The study aimed to determine the cognitive effect of the Val108/158Met polymorphism in the catechol-O-methyltransferase (COMT) gene in children before and during puberty. This polymorphism affects cognitive function in healthy adults and may contribute to risk for schizophrenia. METHOD COMT genotype was determined for 8,707 children from the(More)
OBJECTIVE Genetic variants that contribute to the risk of psychiatric disorders may also affect normal variation in psychological function. Indeed, the behavioral effects of many genetic variants may be better understood as process-specific rather than disease-specific. A functional valine-to-methionine (Val(158)Met) polymorphism in the(More)
Attention-deficit/hyperactivity disorder (ADHD) is a prevalent condition associated with cognitive dysfunction. The Cambridge Neuropsychological Test Automated Battery is a computerized set of tests that has been widely used in ADHD and in translation/back-translation. Following a survey of translational research relevant to ADHD in experimental animals, a(More)
Bipolar disorder is a mood disorder characterized by impairing episodes of mania and depression. Twin studies have established that bipolar disorder is among the most heritable of medical disorders and efforts to identify specific susceptibility genes have intensified over the past two decades. The search for genes influencing bipolar disorder has been(More)