Biomedical subjects

Eric Taylor

Publications and source records attributed to Eric Taylor.

At least 19 recordsLinked to original sources

PubMed2006

Long-acting medications for the hyperkinetic disorders. A systematic review and European treatment guideline.

A systematic review of published and unpublished data on the use of long-acting medications in ADHD and hyperkinetic disorder is reported, giving effect sizes and numbers-to-treat for extended-release stimulant preparations and atomoxetine (ATX). A panel of experts from several European countries used the review to make recommendations about the use of these drugs in practice, and conclusions are reported: (1) Long-acting preparations should be available and used; (2) They should not replace short-acting drugs (which will be the initial treatment for many children for reasons of cost and flexibility of dosing). Individual clinical choice is needed. (3) Both ATX and extended-release preparations of stimulants should be available. The choice will depend upon the circumstances, and detailed recommendations are made.

Atomoxetine Hydrochloride↗

PubMed2006

A common haplotype of the dopamine transporter gene associated with attention-deficit/hyperactivity disorder and interacting with maternal use of alcohol during pregnancy.

CONTEXT: Attention-deficit/hyperactivity disorder (ADHD) is a common heritable childhood behavioral disorder. Identifying risk factors for ADHD may lead to improved intervention and prevention. The dopamine transporter gene (DAT1) is associated with ADHD in several studies, with an average 1.2 odds ratio and evidence of heterogeneity across data sets. OBJECTIVE: To investigate sources of heterogeneity by refining the DAT1 association using additional markers and investigating gene-environment interaction between DAT1 and maternal use of alcohol and tobacco during pregnancy. DESIGN: Prospective study. SETTING AND PATIENTS: Children with ADHD from child behavior clinics in the southeast of England and in the Taipei area of Taiwan. INTERVENTIONS: Within-family tests of association using 2 repeat polymorphisms in the 3' untranslated region and intron 8 plus additional markers in the English sample. MAIN OUTCOME MEASURES: Transmission ratios of risk alleles from heterozygote parents to affected offspring and comparison of the transmission ratios in high- and low-exposure groups for the environmental variables. RESULTS: A novel association was identified between ADHD, the intron 8 polymorphism, and a specific risk haplotype in both English and Taiwanese samples. The risk haplotype showed significant interactions with maternal use of alcohol during pregnancy. CONCLUSIONS: The identification of a common haplotype in 2 independent populations is an important step toward identifying functionally significant regions of DAT1. Interaction between DAT1 genotypes and maternal use of alcohol during pregnancy suggests that DAT1 moderates the environmental risk and has implications for the prevention of ADHD. Further studies are required to delineate the precise causal risk factor involved in this interaction.

Alcohol Drinking↗

PubMed2006

Progressive increase of frontostriatal brain activation from childhood to adulthood during event-related tasks of cognitive control.

Higher cognitive inhibitory and attention functions have been shown to develop throughout adolescence, presumably concurrent with anatomical brain maturational changes. The relatively scarce developmental functional imaging literature on cognitive control, however, has been inconsistent with respect to the neurofunctional substrates of this cognitive development, finding either increased or decreased executive prefrontal function in the progression from childhood to adulthood. Such inconsistencies may be due to small subject numbers or confounds from age-related performance differences in block design functional MRI (fMRI). In this study, rapid, randomized, mixed-trial event-related fMRI was used to investigate developmental differences of the neural networks mediating a range of motor and cognitive inhibition functions in a sizeable number of adolescents and adults. Functional brain activation was compared between adolescents and adults during three different executive tasks measuring selective motor response inhibition (Go/no-go task), cognitive interference inhibition (Simon task), and attentional set shifting (Switch task). Adults compared with children showed increased brain activation in task-specific frontostriatal networks, including right orbital and mesial prefrontal cortex and caudate during the Go/no-go task, right mesial and inferior prefrontal cortex, parietal lobe, and putamen during the Switch task and left dorsolateral and inferior frontotemporoparietal regions and putamen during the Simon task. Whole-brain regression analyses with age across all subjects showed progressive age-related changes in similar and extended clusters of task-specific frontostriatal, frontotemporal, and frontoparietal networks. The findings suggest progressive maturation of task-specific frontostriatal and frontocortical networks for cognitive control functions in the transition from childhood to mid-adulthood.

Adolescent↗

PubMed2006

Systematic review of antimicrobial drug prescribing in hospitals.

Prudent prescribing of antimicrobial drugs to hospital inpatients may reduce incidences of antimicrobial drug resistance and healthcare-associated infection. We reviewed the literature from January 1980 to November 2003 to identify rigorous evaluations of interventions to improve hospital prescribing of antimicrobial drugs. We identified 66 studies with interpretable data, of which 16 reported 20 microbiologic outcomes: gram-negative resistant bacteria, 10 studies; Clostridium difficile-associated diarrhea, 5 studies; vancomycin-resistant enterococci, 3 studies; and methicillin-resistant Staphylococcus aureus, 2 studies. Four studies provided strong evidence that the intervention changed microbial outcomes with low risk for alternative explanations, 8 studies provided less convincing evidence, and 4 studies provided no evidence. The strongest and most consistent evidence was for C. difficile-associated diarrhea, but we were able to analyze only the immediate impact of interventions because of nonstandardized durations of follow-up. The ability to compare results of studies could be substantially improved by standardizing methods and reporting.

Anti-Bacterial Agents↗

PubMed2005

Family-based association study of serotonin transporter gene polymorphisms in attention deficit hyperactivity disorder: no evidence for association in UK and Taiwanese samples.

Five independent studies have reported associations between serotonin transporter gene (5-HTT) polymorphisms and attention deficit hyperactivity disorder (ADHD). Four studies found evidence for association between the long-allele of a 44-base pair insertion/deletion polymorphism (5-HTTLPR), one of the studies found association to a variable number tandem repeat within intron 2, another to the T-allele of a single base pair substitution in the 3'-untranslated regions and another reported preferential transmission of a haplotype of the three markers (long-allele/10-repeat-allele/T-allele). One further study found no evidence for these associations. We investigated the association of these three markers in two samples of ADHD patients from the United Kingdom (n = 197) and Taiwan (n = 212), using within-family tests of association. No association was found between any of the three markers in either of the two populations. Although we found some evidence for the preferential transmission of a rare haplotype (long-allele/9-repeat-allele/T-allele; chi2 = 4.5, P = 0.034), we concluded that this most likely occurred by chance factors alone.

Adolescent↗

PubMed2005

DNA pooling analysis of 21 norepinephrine transporter gene SNPs with attention deficit hyperactivity disorder: no evidence for association.

The norepinephrine system is known to play a role in attentional and cognitive-energetic mechanisms and is thought to be important in attention deficit hyperactivity disorder (ADHD). Stimulant medications are known to alter the activity of norepinephrine as well as dopamine in the synapse and the highly selective norepinephrine reuptake inhibitor, atomoxetine, is an effective treatment for ADHD symptoms. This study set out to investigate whether common polymorphisms within the norepinephrine transporter gene (NET1) are associated with DSM-IV ADHD combined subtype, using a sample that has previously shown association with genes that affect the synaptic release and uptake of neurotransmitters; DAT1 and SNAP-25. We identified 21 single nucleotide polymorphisms (SNPs) from publicly available databases that had minor allele frequencies > or =5% and span the NET1 genomic region, including those analyzed in previous studies of ADHD. DNA pooling was used to screen for associations using two case pools (n = 180 cases) and four control pools (n = 334 controls). We identified three SNPs that showed suggestive evidence for association using either case-control or within family tests of association, however, none of these were significant after adjustment for the number of markers analyzed. We conclude that none of the markers show significant evidence of association with ADHD although we cannot rule out small genetic effects.

Algorithms↗

PubMed2005

The adolescent outcome of hyperactive girls. Self-reported interpersonal relationships and coping mechanisms.

The aim of the study was to clarify the developmental risk for interpersonal relationship problems and ineffective coping strategies associated with hyperactive behaviour in girls in a longitudinal epidemiological design. This was investigated in a follow-up study of girls who were identified by parent and teacher ratings in a large community survey of 6- and 7-year-olds as showing pervasive hyperactivity or conduct problems or the comorbid mixture of both problems or neither problem. They were later investigated, at the age of 14-16 years, in a detailed interview. Childhood hyperactivity was a risk for disrupted relationships in adolescence with peers and the opposite sex, but not parents. Findings were independent of the existence of conduct problems. Hyperactivity was a risk for the use of a wide variety of ineffective coping strategies. On the other hand, conduct problem girls reported applying specific coping strategies, but rated these to be ineffective. It is concluded that early therapeutic interventions targeting the development of social skills and problem-solving skills are required in order to help overcome these problems in later life.

Adaptation, Psychological↗

PubMed2005

Psychiatric diagnoses and behaviour problems from childhood to early adolescence in young people with severe intellectual disabilities.

BACKGROUND: While general population studies indicate an increase in the rate of psychiatric disorder in adolescence, little is known about the course of mental health and behaviour problems between childhood and adolescence in young people with severe intellectual disabilities. METHOD: From a sample of 111 children with severe intellectual disability who had been identified from the registers of six special schools at 4-11 years of age, 82 were traced and reassessed 5 years later at the age of 11-17 years. Behaviour problems were assessed by means of parental interviews conducted in the family home and parent and teacher questionnaires. Parental reports of psychiatric diagnoses were checked against health records. RESULTS: With most behaviour problems, including aggression, destructive behaviour and self-injury, there was little difference in rates between the two assessment occasions. However, in spite of this overall pattern of stability, the rates of some behaviour problems, including overactivity, showed significant reductions between childhood and early adolescence. Persistence rates for most behaviour problems appeared comparable to those reported for similar behaviours in general population studies of children. There was no significant difference in the proportion of cases with psychiatric diagnoses between the two assessment occasions, although brief psychotic episodes emerged in three cases in adolescence. CONCLUSIONS: The findings suggest that the prevalence of mental health and behavioural problems in young people with severe learning disabilities remains relatively stable between childhood and adolescence, although some specific behaviour problems diminish. However, a small minority of children may develop severe psychiatric disorders in adolescence.

Adolescent↗

PubMed2005

ADHD.

Explore the source record for details and available documents.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Towards an understanding of unique and shared pathways in the psychopathophysiology of ADHD.

Most attention deficit hyperactivity disorder (ADHD) research has compared cases with unaffected controls. This has led to many associations, but uncertainties about their specificity to ADHD in contrast with other disorders. We present a selective review of research, comparing ADHD with other disorders in neuropsychological, neurobiological and genetic correlates. So far, a specific pathophysiological pathway has not been identified. ADHD is probably not specifically associated with executive function deficits. It is possible, but not yet established, that ADHD symptoms may be more specifically associated with motivational abnormalities, motor organization and time perception. Recent findings indicating common genetic liabilities of ADHD and other conditions raise questions about diagnostic boundaries. In future research, the delineation of the pathophysiological mechanisms of ADHD needs to match cognitive, imaging and genetic techniques to the challenge of defining more homogenous clinical groups; multi-site collaborative projects are needed.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

The adolescent outcome of hyperactive girls: self-report of psychosocial status.

BACKGROUND: The aim of the study was to clarify the developmental risk associated with hyperactive behaviour in girls in a longitudinal epidemiological design. METHODS: This was investigated in a follow-up study of girls who were identified by parent and teacher ratings in a large community survey of 6- and 7-year-olds as showing pervasive hyperactivity or conduct problems or the comorbid mixture of both problems or neither problem. They were later investigated, at the age of 14 to 16 years, with a detailed self-report interview technique. RESULTS: Hyperactivity was a risk factor for later development, even allowing for the coexistence of conduct problems. Hyperactivity predicted academic problems and interpersonal relationship problems. Relationships with parents, by contrast, were not portrayed to be as problematic as relationships with peers and the opposite sex. Their psychological, social and occupational functioning was objectively rated to be more deviant and their self-report showed them to be more ambivalent about their future. There was a trend for hyperactivity to be self-reported as a risk for the development of continuing symptomatology but neither hyperactivity nor conduct problems were self-reported to be a risk for antisocial behaviour, substance misuse or low self-esteem in adolescence. However, they were at risk for the development of state anxiety. CONCLUSIONS: The results suggested girls' pattern of functioning may differ from that of boys because girls self-report a more pervasive range of social dysfunction than that previously reported in boys.

Achievement↗

PubMed2005

Practitioner review: early adversity and developmental disorders.

BACKGROUND: Knowledge of genetic influences, on developmental disorders such as autism spectrum, attention deficit/hyperactivity disorder and learning disabilities, has increased the opportunities for understanding the influences of the early environment. METHODS: This paper provides a selective, narrative review for clinicians of the effects of factors such as exposure to toxins and stresses in utero and in postnatal life; brain injuries and perinatal compromise; neglect, malnutrition and selective food deficiencies. It also considers what is known about the mechanisms through which early adversities operate. RESULTS: Gaps in the research are identified and suggestions made about clinical investigations. Several types of environmental adversity have associations with later disorders that suggest a causal role. The effects are often on a broad range of psychological processes, and are not always quickly reversible. Several adversities often coexist, calling for skilled judgement about priorities in treatment. CONCLUSIONS: Individuals vary considerably in their exposure to adversity and their vulnerability to its effects, and genetic inheritance can influence both.

Attention Deficit Disorder with Hyperactivity↗

PubMed2005

Abnormal brain activation during inhibition and error detection in medication-naive adolescents with ADHD.

OBJECTIVE: Patients with attention deficit hyperactivity disorder (ADHD) and a medication history have shown abnormal brain activation in prefrontal and striatal brain regions during cognitive challenge. Previous findings have been confounded, however, by potential long-term effects of stimulant medication exposure and group discrepancies in task performance. The aim of this study was to investigate whether medication-naive adolescents with ADHD would still show abnormal brain activation in prefrontal brain regions during motor response inhibition in a task designed to control for intergroup performance discrepancies. METHOD: Rapid, event-related functional magnetic resonance imaging was used to compare brain activation in 16 medication-naive ADHD adolescents and 21 IQ-, age-, and sex-matched healthy comparison volunteers during a challenging, idiosyncratically adjusted task that required withholding of a triggered motor response. The design, which manipulated task parameters to force each subject to fail on 50% of trials, ensured that subjects worked at the edge of their own inhibitory performance, thereby controlling for intersubject and intergroup performance discrepancies and furthermore allowing for investigation of differences in brain activation related to inhibition and inhibition failure. RESULTS: Medication-naive adolescents with ADHD showed significantly reduced brain activation in the right inferior prefrontal cortex during successful motor response inhibition and in the precuneus and posterior cingulate gyrus during inhibition failure, both of which correlated with behavioral scores of ADHD. CONCLUSIONS: The study shows that abnormal brain activation during inhibitory challenge in ADHD is specific to the disorder, since it persists when medication history and performance discrepancies are excluded.

Adolescent↗

PubMed2005

Unravelling the complexity of attention-deficit hyperactivity disorder: a behavioural genomic approach.

International research has established that there is a strong genetically inherited contribution to attention-deficit hyperactivity disorder (ADHD) and the genetic mechanisms involved are being sought with considerable success. It is now established that certain alleles of the genes coding for the dopamine D4 receptor and the dopamine transporter occur more frequently in children with ADHD than in healthy controls, and we are finding other DNA changes associated with ADHD. A major challenge for the field now is to clarify how genetic susceptibility is translated into disorder by integrating the fields of quantitative and molecular genetics, neuropsychology and environmental risks.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Polymorphisms in the dopamine D5 receptor (DRD5) gene and ADHD.

There is considerable evidence to support a role of dopamine-related genes in the molecular aetiology of attention-deficit hyperactivity disorder (ADHD). A microsatellite located near the dopamine D5 receptor (DRD5) gene has been associated with ADHD in a number of studies, but other polymorphisms within the vicinity of this gene have not been examined. In this study we genotyped three microsatellites spanning the DRD5 region in a large clinical sample. Overall, we found little evidence to support a role for DRD5 in ADHD. We found no evidence of association with either the previously associated DRD5 marker, or a repeat in the promoter region of the gene. We did, however, find significant association for an allele of D4S615, a dinucleotide repeat located 131 kb 3' of DRD5 that has been previously associated with schizophrenia. A global test incorporating all alleles of this marker, however, was not significant and thus this finding needs replication before any conclusions can be made.

Attention Deficit Disorder with Hyperactivity↗

PubMed2004

Neural correlates of switching set as measured in fast, event-related functional magnetic resonance imaging.

Attentional switching has shown to involve several prefrontal and parietal brain regions. Most cognitive paradigms used to measure cognitive switching such as the Wisconsin Card Sorting Task (WCST) involve additional cognitive processes besides switching, in particular working memory (WM). It is, therefore, questionable whether prefrontal brain regions activated in these conditions, especially dorsolateral prefrontal cortex (DLPFC), are involved in cognitive switching per se, or are related to WM components involved in switching tasks. Functional magnetic resonance imaging (fMRI) was used to examine neural correlates of pure switching using a paradigm purposely designed to minimize WM functions. The switching paradigm required subjects to switch unpredictably between two spatial dimensions, clearly indicated throughout the task before each trial. Fast, event-related fMRI was used to compare neural activation associated with switch trials to that related to repeat trials in 20 healthy, right-handed, adult males. A large cluster of activation was observed in the right hemisphere, extending from inferior prefrontal and pre- and postcentral gyri to superior temporal and inferior parietal cortices. A smaller and more caudal cluster of homologous activation in the left hemisphere was accompanied by activation of left dorsolateral prefrontal cortex (DLPFC). We conclude that left DLPFC activation is involved directly in cognitive switching, in conjunction with parietal and temporal brain regions. Pre- and postcentral gyrus activation may be related to motor components of switching set.

Adult↗

PubMed2004

PTSD and depression in refugee children: associations with pre-migration trauma and post-migration stress.

This paper describes the effect of pre-migration and post-migration experiences on the mental health of a sample of 40 refugee children aged 8-16 who lived in London with at least one parent or a refugee relative. Children's post-traumatic stress disorder (PTSD) and depression symptoms were assessed with standardised self-report measures (Impact of Event Scale and Depression Self-Rating Scale for Children, respectively). Information regarding past and present experiences were gathered during an interview with parents. There was a significant correlation between the number of pre-migration traumas experienced by the families and the children's PTSD scores. There was also a significant correlation between the families' number of post-migration stresses and children's depression scores. Higher PTSD scores were significantly associated with the pre-migration experience of violent death of family members and the post-migration experience of an insecure asylum status. Higher depression scores were significantly associated with insecure asylum status and severe financial difficulties. The clinical implications of these findings are discussed.

Adolescent↗

PubMed2004

European clinical guidelines for hyperkinetic disorder -- first upgrade.

BACKGROUND: The validity of clinical guidelines changes over time, because new evidence-based knowledge and experience develop. OBJECTIVE: Hence, the European clinical guidelines on hyperkinetic disorder from 1998 had to be evaluated and modified. METHOD: Discussions at the European Network for Hyperkinetic Disorders (EUNETHYDIS) and iterative critique of each clinical analysis. Guided by evidence-based information and based on evaluation (rather than metaanalysis) of the scientific evidence a group of child psychiatrists and psychologists from several European countries updated the guidelines of 1998. When reliable information is lacking the group gives a clinical consensus when it could be found among themselves. RESULTS: The group presents here a set of recommendations for the conceptualization and management of hyperkinetic disorder and attention deficit/hyperactivity disorder (ADHD). CONCLUSION: A general scheme for practice in Europe could be provided, on behalf of the European Society for Child and Adolescent Psychiatry (ESCAP).

Alleles↗