Biomedical subjects

A L Vance

Publications and source records attributed to A L Vance.

4 recordsLinked to original sources

PubMed2000

Magnetic resonance spectroscopy and schizophrenia: what have we learnt?

OBJECTIVE: Magnetic resonance spectroscopy (MRS) has been increasingly used to investigate the in vivo biochemistry of particular regions of the brain in patients with schizophrenia. We review the literature and discuss the theoretical constructs that form the presumed impetus for these studies in light of the current methodological limitations. Future directions are noted. METHOD: The available published literature in English formed the basis for this review. RESULTS: The results of 31P-MRS have been interpreted as reflecting a relative increase in cell membrane degradation in prefrontal cortical regions at certain phases of schizophrenia. 1H-MRS studies, though less consistent, provide evidence suggestive of a decrease in neuronal cell mass in the hippocampal region, which supports the findings of volumetric studies. Both groups of MRS studies support a neuro-developmental hypothesis of brain dysfunction in schizophrenia. However, current methodological problems limit the reliable interpretation of MRS data. A clear understanding of the methodology and its reliable interpretation is yet to emerge. CONCLUSIONS: MRS remains a research instrument that is yet to be fully utilised in schizophrenia research. A few replicated findings are emerging, although the interpretation of these spectroscopic findings needs to be validated.

Brain↗

PubMed2000

Attention deficit hyperactivity disorder: current progress and controversies.

OBJECTIVE: Attention deficit hyperactivity disorder (ADHD) is a common chronic and disabling condition in children. This paper reviews the taxonomic issues and the major comorbid conditions, neurobiological correlates, treatment and public health issues associated with ADHD. METHOD: Pertinent recent papers are reviewed from the psychological and psychiatric literature. RESULTS: The two major taxonomies now define a similar group of children with ADHD of a combined type/hyperkinetic disorder. Advances in the understanding and treatment of ADHD demonstrate the complex multidimensional links between neurobiology, psychology and behaviour. Careful assessment of individual factors in treatment planning and ongoing monitoring of psychostimulant medication treatment in the longer term are recommended. CONCLUSIONS: There is much still to learn about ADHD, and increased levels of clinical research and treatment resources are required.

Anxiety Disorders↗

PubMed1999

Attention deficit hyperactivity disorder: anxiety phenomena in children treated with psychostimulant medication for 6 months or more.

OBJECTIVE: The intermediate- to long-term use of psychostimulant medication has unclear benefits on the core symptoms of attention deficit hyperactivity disorder (ADHD) and delayed onset affective symptom side effects which can mimic these core ADHD symptoms. 'ADHD and anxiety' has also been associated with a poor response to short-term psychostimulant medication treatment. In addition, it is unclear whether 'ADHD and anxiety' should be defined from the child's and/or the parent's perspective. We propose that anxiety will be increased in children with ADHD who are treated with psychostimulant medication in the intermediate- to long-term who are identified by clinicians as poor responders. METHOD: Twenty children with ADHD who were medicated for 6 months or more and who had ongoing core symptoms of ADHD were compared to 20 age- and IQ-matched children with ADHD who were medication-naïve. Chi-squared tests were performed on the categorical dependent variables and independent t-tests on the dependent continuous variables. RESULTS: Anxiety is significantly increased in children with ADHD treated with psychostimulant medication in the intermediate- to long-term who are noted by clinicians to have ongoing core symptoms of ADHD. This statistically significant finding is evident with both categorical and dimensional measures of anxiety from the child's perspective. CONCLUSIONS: The recognition of anxiety and its management in children with ADHD is generally poorly understood. In this particular group of children with ADHD, anxiety may be a side effect of intermediate- to long-term psychostimulant medication and/or a potential marker for a poor response to intermediate- to long-term psychostimulant medication treatment.

Anxiety↗

PubMed1998

Attention deficit hyperactivity disorder and anxiety: is there an association with neurodevelopmental deficits?

OBJECTIVE: The co-occurrence of attention deficit hyperactivity disorder (ADHD) and anxiety is a well-established clinical observation. However, its status as a clinical construct is debated. We review the prevalence of 'ADHD and anxiety', its definitions, and its clinical correlates and we hypothesise that neurodevelopmental deficits may be increased in 'ADHD and anxiety'. METHOD: The authors identified empirical studies in the psychiatric and psychological literature. The search categories included hyperactivity, attention deficit hyperactivity disorder, attention deficit disorder and anxiety. RESULTS: 'ADHD and anxiety' is considerably more common in clinical than epidemiological samples. There are a range of definitions which address the situational variation in both ADHD and anxiety symptoms and the use of categorical and continuous variables to define them. Yet the nature of the anxiety is still unclear. It is associated with a poor response to psychostimulant medication treatment, and alternative pharmacotherapy approaches have been suggested. There is a controversy about whether neurodevelopmental deficits are associated with hyperactivity alone, or anxiety, or both. CONCLUSIONS: 'ADHD and anxiety' is important clinically because it is common and less responsive to psychostimulant medication. Important research issues include its heterogeneity which necessitates the collection of parent, teacher, and child self-reports of symptoms' presence or absence and the hypothesis that neurodevelopmental deficits may be increased in this group of children.

Antidepressive Agents↗