Solving The Jigsaw! Understanding Biological And Environmental Effects On ADHD Through Discordant Mononozygotic Twins
Funder
National Health and Medical Research Council
Funding Amount
$557,500.00
Summary
The recent Child and Adolescent component of the National Mental Health Survey identified Attention Deficit Hyperactivity Disorder(ADHD) as the most common behavioural problem among Australian children. Since 1991 our Australian Twin ADHD Project (ATAP) has developed as one of the world's largest programs on the genetics of ADHD, and in 2001 we published the first text on this topic. In this grant we turn the focus onto environmental influences with the question Why can one identical twin have A ....The recent Child and Adolescent component of the National Mental Health Survey identified Attention Deficit Hyperactivity Disorder(ADHD) as the most common behavioural problem among Australian children. Since 1991 our Australian Twin ADHD Project (ATAP) has developed as one of the world's largest programs on the genetics of ADHD, and in 2001 we published the first text on this topic. In this grant we turn the focus onto environmental influences with the question Why can one identical twin have ADHD, while the other twin has no difficulties? Using the unique resources of the Australian Twin Registry and the WA Twin Child Health Study, we shall work across the country to find over 100 identical twin pairs who are very different in ADHD. In this way, each ADHD affected twin has an unaffected 'control twin', offering a powerful means for comparing the two. Such a study is really only possible in Australia, as no other country has such twin resources for research. The questions we want to consider with these children include the following 1- Twins have a more difficult time before and at birth. To what extent do these problems contribute to differences between the twins? 2- Are there differences in specific aspects of brain functioning? 3- Is it that one twin grows out of their ADHD but the other does not? If so, what distinguishes the children? 4- What is it like growing up with a twin who has ADHD, when you have no difficulties yourself? 5- When one twin has ADHD symptoms, is the family more likely to seek help, as they can see how different this child is form the other twin? Obviously identical twins in wehich only one has ADHD are a very unique group. By covering all aspects of development, from brain functioning to service utilisation, the hope is that this study will provide invaluable insights into this common condition which will help all children and families where the diagnosis of ADHD has been made.Read moreRead less
Structural And Diffusion Tensor Neuroimaging In Twins Concordant And Discordant For Psychosis.
Funder
National Health and Medical Research Council
Funding Amount
$477,375.00
Summary
Measures from specialised brain scans i.e. MRI's (Magnetic Resonance Imaging) have suggested that several areas in the brain are different in those individuals who suffer from psychosis compared to those who don't. Evaluations of these brain differences have helped us better understand the nature of these illnesses. For example, frontal lobe dysfunction has been linked with the loss of ability to plan and organize information, seen in those who have schizophrenia. These measures may also help cl ....Measures from specialised brain scans i.e. MRI's (Magnetic Resonance Imaging) have suggested that several areas in the brain are different in those individuals who suffer from psychosis compared to those who don't. Evaluations of these brain differences have helped us better understand the nature of these illnesses. For example, frontal lobe dysfunction has been linked with the loss of ability to plan and organize information, seen in those who have schizophrenia. These measures may also help clarify the relationship between the genetic and environmental factors contributing to the development of these disorders. One of the best ways to investigate this relationship is the use of a twin study design. The Australian study of twins with psychosis will recruit dizygotic (DZ) and monozygotic (MZ) twin pairs in which at least one twin is affected by a psychotic disorder, plus control twin pairs matched for age, sex and zygosity. Measures derived from MRI scans will be collected in an attempt to further define specific brain regions reported to be different in psychosis. In addition Diffusion Tensor Imaging (DTI) will be used to visualize white matter tracts in the brain. The twin study design will allow us to differentiate genetic and environmental factors associated with these brain measures and help evaluate the potential for these measures to genetically define sub-groups of individuals with psychotic disorders. The identification of these subgroups would facilitate the search for susceptibility genes. Additionally, this study will help clarify the possible clinical overlap between affective (i.e. bipolar affective disorder) and non-affective (i.e. schizophrenia) psychotic disorders. The information obtained from this study has the potential to greatly improve our understanding of caustive factors in psychosis, which may also lead to earlier diagnosis and treatment, thereby improving prognosis.Read moreRead less