Twin and family studies show schizophrenia has a genetic basis. Attempts to find and characterise the underlying genes have not been successful so far. A main reason for this is that insufficient attention has been paid to the complexity of the underlying genetic architecture of the disorder. The pathway from genes to symptoms of schizophrenia is likely to involve elementary processes at neuronal and neural circuitry levels that vary between individuals and this variation is reflected in a grade ....Twin and family studies show schizophrenia has a genetic basis. Attempts to find and characterise the underlying genes have not been successful so far. A main reason for this is that insufficient attention has been paid to the complexity of the underlying genetic architecture of the disorder. The pathway from genes to symptoms of schizophrenia is likely to involve elementary processes at neuronal and neural circuitry levels that vary between individuals and this variation is reflected in a graded susceptibility to schizophrenia. During the last three years we have recruited a large number of families with at least one family member diagnosed with schizophrenia. The proband and all participating first-degree relatives have been assessed with a neurocognitive test battery including measures of sustained attention, working memory, speed of information processing, auditory verbal learning and executive function. Analysis of the neurocognitive data on this sample produced strong evidence that several measures are altered in patients with schizophrenia and a proportion of their asymptomatic first-degree relatives compared to unrelated normal controls. In the study we will systematically search the human genome for DNA markers linked to these measures. This will set the stage for the systematic search and characterisation of the underlying genes. This will allow us to better understand the predisposition to develop schizophrenia. In the individual case it is likely that this vulnerability results from a high-risk combination of a number of relatively common alleles which contribute to basic neural processes.Read moreRead less
Understanding The Molecular Basis Of Bipolar Affective Disorder
Funder
National Health and Medical Research Council
Funding Amount
$812,250.00
Summary
Bipolar disorder (manic depressive illness) is a severe mood disorder, with a lifetime prevalence of up to 1.6%. The illness is characterised by aberrant mood swings resulting in periods of mania and depression with reversion to normal behaviour between episodes. The condition has a severe impact on sufferers, being demonstrated to be the sixth most disabling disorder in the WHO Global Burden of Disease report and increasing the risk of suicide fifteen-fold. There is a pressing need to define mo ....Bipolar disorder (manic depressive illness) is a severe mood disorder, with a lifetime prevalence of up to 1.6%. The illness is characterised by aberrant mood swings resulting in periods of mania and depression with reversion to normal behaviour between episodes. The condition has a severe impact on sufferers, being demonstrated to be the sixth most disabling disorder in the WHO Global Burden of Disease report and increasing the risk of suicide fifteen-fold. There is a pressing need to define more clearly the biological basis of bipolar disorder as a necessary prerequisite to improved diagnosis and treatment. The underlying causes of bipolar disorder remain unknown. However, family studies reveal the high heritability of bipolar disorder and this familial clustering provides an opportunity to use genetic approaches to identify the predisposing genes. The long-term aim of our research is to investigate the biology of those genes that either cause or predispose to bipolar disorder. We have previously reported strong evidence for a novel bipolar disorder susceptibility gene on chromosome 4, a finding which has subsequently been reproduced in several independent studies. Consequently, we hypothesise that there is a gene located on chromosome 4 that predisposes to bipolar disorder. The aim of this proposal is to identify the chromosome 4 bipolar susceptibility gene and understand how the gene causes bipolar disorder. Identifying the genes responsible for bipolar disorder will allow us to define and understand the biological basis of this severe psychiatric condition. This will ultimately lead to major improvements in the ability to diagnose, treat and prevent the illness.Read moreRead less
Dissecting the shared genetic architecture of psychiatric and psychological traits with application to prediction of genetic risk. Identification of the early phase of psychiatric disorders is considered critical for early intervention which is the essence of prevention. At present, the main obstacle to targeted early intervention strategies in psychiatric disorders is the non-specific nature of early stage symptoms. Many psychiatric disorders present with symptoms of depressed mood and anxiety ....Dissecting the shared genetic architecture of psychiatric and psychological traits with application to prediction of genetic risk. Identification of the early phase of psychiatric disorders is considered critical for early intervention which is the essence of prevention. At present, the main obstacle to targeted early intervention strategies in psychiatric disorders is the non-specific nature of early stage symptoms. Many psychiatric disorders present with symptoms of depressed mood and anxiety in the early stages, yet best intervention treatments are dependent on the final (unknown) diagnosed disorder. Prediction of genetic risk is likely to make an important contribution for identification of individuals at risk of specific psychiatric disorders so that the best early intervention treatment can be administered. Read moreRead less
ADHD Grown-up: Genetic And Environmental Determinants Of The Adult Outcomes Of Childhood ADHD And Comorbid Conditions
Funder
National Health and Medical Research Council
Funding Amount
$289,542.00
Summary
ADHD remains a controversial issue especially in adulthood. There are many related behavioural problems including substance abuse, anxiety, depression, and personality disorders. Australia is such a focus for twin research that many twin families have taken part in several studies of different aspects of mental health over the years. This grant allows us to link the various datasets to create a unique longitudinal genetic resource and to examine the longterm outcomes.