Neurobiological investigations of substance use and psychosis.
Despite the understanding that methamphetamine use increases the risk for and exacerbates psychosis, few studies have investigated the underlying neurobiology. Young people with methamphetamine psychosis present with very similar symptoms to first episode psychosis in schizophrenia. This study aims to distinguish between these groups using neurobiological markers. The findings will help identify methamphetamine users who may be at risk of psychosis and reveal important information about the underlying mechanism of schizophrenia.
This study will employ neurophysiological (i.e. electroencephalography: EEG and event-related potential: ERP) measures in conjunction with tests of neuropsychological function (e.g. attention, memory, executive functioning) to assess individuals who experience psychotic symptoms (hallucinations, paranoia) with and without methamphetamine use. This study is part of a wider research program and therefore may include the examination of several different groups, i.e. young people (16 to 30 yrs old) who have psychotic symptoms (1) after methamphetamine use; (2) with no history of methamphetamine use; (3) which preceded methamphetamine use; and (4) which follow other substance use (e.g. cannabis). It is expected that patterns of association between neurophysiological and neuropsychological markers will emerge as neurobiological markers of psychosis. Furthermore, this research will reveal important markers which reflect common neural substrates in psychosis versus other markers which may be specific to different types of psychosis. The study assessments would include: (1) clinical screening for psychosis and other mental health problems; (2) neurophysiological (EEG/ERP) and neuropsychological (including the CANTAB touch screen computer test battery) assessment; and (3) drug screening. There is also the opportunity to engage with other research facilities available at the BMRI such as brain imaging (MRI, PET); genotyping; sleep and chronobiology; cognitive remediation, driving simulator and eye tracking. Psychotic disorders in young people are associated with high rates of disability and poor psychosocial outcomes. Both the symptoms of psychosis as well as the inherent cognitive impairment are reflective of significant neurobiological changes. Efforts to delineate early markers of people at risk of psychosis are therefore highly warranted. One obvious at-risk group is young people using amphetamines. Indeed, psychosis associated with substance use is predictive of poor prognosis and is likely to reflect additional neurotoxic mechanisms. This study will help delineate early neurobiological changes using robust measures of subtle brain dysfunction (e.g. ERP markers of schizophrenia) in conjunction with cognitive measures (e.g. working memory). It is increasingly recognised that identification of neurobiological changes in psychosis can help target early intervention and neuroprotective approaches. This may be particularly relevant during critical developmental periods such as adolescence and young adulthood. This research, therefore, will guide such early intervention approaches in order to prevent substance-associated brain changes in those at risk of psychosis, maximise educational/vocational outcomes, psychosocial functioning, and reduce rates of disability.
Candidates would be trained in electroencephalography techniques. Candidates would also gain skills in the collection of clinical and neuropsychological data. Other training in brain imaging, drug screening and phlebotomy would also become available. The BMRI provides candidates with excellent clinical research experience as there is a clinical centre within the facility and association with a range of specialised referral services (e.g. Headspace).
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The opportunity ID for this research opportunity is: 748
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