Risk Factors For Compliance With Command Hallucinations In Psychotic Disorders
Funder
National Health and Medical Research Council
Funding Amount
$180,290.00
Summary
There is widespread public concern about the danger individuals with schizophrenia or related disorders pose to themselves and to the community. Whilst a number of violence risk factors such as being male, exhibiting hostility, and having a prior history of violence are well established, they are of limited use to clinicians in making management decisions. Our study will investigate a different approach to identify individuals and occasions when a sufferer might require more intensive care or ob ....There is widespread public concern about the danger individuals with schizophrenia or related disorders pose to themselves and to the community. Whilst a number of violence risk factors such as being male, exhibiting hostility, and having a prior history of violence are well established, they are of limited use to clinicians in making management decisions. Our study will investigate a different approach to identify individuals and occasions when a sufferer might require more intensive care or observation. Most individuals with schizophrenia experience auditory hallucinations. Amongst these hallucinations, voices that command the individual to undertake a particular action are common; many of these involve significant potential harm to the hallucinator or to other persons. We will attempt to identify those factors that are associated with an individual obeying command hallucinations. Variables to be examined include the characteristics of the hallucinated voices, and the beliefs of the subject about the power of the voices. Subjects will be interviewed to find out whether they have delusions that are consistent with their hallucinations, whether they suffer from Antisocial Personality Disorder, or are dependent on alcohol or drugs. We will also determine whether subjects who report being raised by authoritarian parents, who are dependent on the approval of others, or who see external factors as determining the occurrence of major events in their lives, are more likely to act on their hallucinations. Two groups of 100 patients will be studied. One group will be representative of people living in the community with schizophrenia. The other group will be people with schizophrenia who have been treated by the State Forensic Psychiatric Services. Statistical models will be developed in order to determine the accuracy with which compliance with command hallucinations can be predicted. These models with also reveal which risk factors are the most important.Read moreRead less
Abnormal Auditory System Function In Schizophrenia: An ERP And MEG Study Of Its Origin, Course And Generality.
Funder
National Health and Medical Research Council
Funding Amount
$250,770.00
Summary
In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding i ....In 1991, an Australian group found that schizophrenia patients have a reduced brain response to deviant sounds in a repeating pattern of identical sounds. Deviant sounds produce a brain electrical response known as mismatch negativity which is generated by the auditory cortex in the brain's temporal lobes and by adjacent areas in the frontal lobes. A smaller mismatch negativity in patients has since been replicated in laboratories in the US, Europe and Australia. The importance of this finding is that it had not been previously recognised that patients have low level auditory problems that could potentially have a profound impact on higher level functions. Finnish researchers have gone on to show in healthy individuals that mismatch negativity can reveal important features about how well the auditory system works, e.g., for the brain to respond to a deviant sound, it must have a memory of what happened in the past. Mismatch negativity provides a measure of the integrity of these memory functions. But it also provides an index of how well the auditory system discriminates different aspects of sound, pitch, loudness, and temporal features, such as duration. There are hints in our data and from US researchers that processing of the temporal features of sounds is particularly impaired in schizophrenia. We have also recently discovered that first-degree relatives of patients may have a similar deficit. The aim of this project is to use mismatch negativity to probe what is wrong with the auditory system in schizophrenia and those at risk (first degree relatives). Is it the areas of the brain primarily involved in sound perception (the temporal lobes) that are faulty or is the problem in the frontal lobes? Is it the case that processing of temporal features are particularly compromised and if so, is this a biological marker for schizophrenia. Answers to these questions will greatly enhance our understanding of the nature of the brain dysfunction in schizophrenia.Read moreRead less