Melbourne School of Psychological Sciences - Research Publications
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ItemCan youth at high risk of illness progression be identified by measures of rumination and sleep-wake disturbance(WILEY, 2019-10)AIM: Clinical staging models offer a useful framework for understanding illness trajectories, where individuals are located on a continuum of illness progression from stage 0 (at-risk but asymptomatic) to stage 4 (end-stage disease). Importantly, clinical staging allows investigation of risk factors for illness progression with the potential to target trans-diagnostic mechanisms at an early stage, especially in help-seeking youth who often present with sub-threshold syndromes. While depressive symptoms, rumination and sleep-wake disturbances may worsen syndrome outcomes, the role of these related phenomena has yet to be examined as risk factors for trans-diagnostic illness progression in at-risk youth. METHODS: This study is a prospective follow-up of 248 individuals aged 12 to 25 years presenting to headspace services with sub-threshold syndromes (stage 1) classified under the clinical staging model to determine transition to threshold syndromes (stage 2). Factor analysis of depression, rumination and sleep-wake patterns was used to identify key dimensions and any associations between factors and transition to stage 2 at follow-up. RESULTS: At 1 year, 9% of cases met criteria for stage 2 (n = 22). One of three identified factors, namely the factor reflecting the commonalities shared between rumination and sleep-wake disturbance, significantly differentiated cases that transitioned to stage 2 vs those that did not demonstrate transition. Items loading onto this factor, labelled Anergia, included depression severity and aspects of rumination and sleep-wake disturbance that were characterized as introceptive. CONCLUSIONS: Common dimensions between rumination and sleep-wake disturbance present a detectable trans-diagnostic marker of illness progression in youth, and may represent a target for early intervention.
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ItemStability of retrospective self-reports of childhood trauma in first-episode psychosis(WILEY, 2019-08)AIM: Childhood trauma (CT), abuse and neglect are commonly reported by individuals experiencing psychosis. However, there are concerns that acute psychotic symptoms, in particular delusions, may contribute to inaccurate reporting of CT. As a result, individuals experiencing psychosis may not be asked about their experiences of abuse when they are being seen in psychiatric settings. This lack of attention can directly impact on the tailoring of their clinical care. This study aimed to investigate the stability of reports of CT by young people experiencing a first psychotic episode (FEP) compared to healthy comparison subjects. METHODS: Responses of 24 young people during the acute FEP and 3 months later to items on the Childhood Trauma Questionnaire (CTQ) were compared to 30 non-psychiatric controls. All participants were aged 15 to 25 years. RESULTS: FEP participants reported higher CT than controls at both time points. Reliability analyses (interclass correlation coefficients [ICCs]) suggested strong agreement between CT reports at baseline and follow-up for FEP participants (.81) and controls (.91). Positive psychotic symptoms were unrelated to CT reports. Although the severity of CT reports fluctuated between assessments, complete retractions of severe abuse claims occurred rarely. CONCLUSIONS: The results suggest that retrospective self-report can be used to reliably assess CT in young people experiencing acute psychosis.
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ItemReduced parahippocampal cortical thickness in subjects at ultra-high risk for psychosis(CAMBRIDGE UNIV PRESS, 2014-02)BACKGROUND: Grey matter volume and cortical thickness represent two complementary aspects of brain structure. Several studies have described reductions in grey matter volume in people at ultra-high risk (UHR) of psychosis; however, little is known about cortical thickness in this group. The aim of the present study was to investigate cortical thickness alterations in UHR subjects and compare individuals who subsequently did and did not develop psychosis. METHOD: We examined magnetic resonance imaging data collected at four different scanning sites. The UHR subjects were followed up for at least 2 years. Subsequent to scanning, 50 UHR subjects developed psychosis and 117 did not. Cortical thickness was examined in regions previously identified as sites of neuroanatomical alterations in UHR subjects, using voxel-based cortical thickness. RESULTS: At baseline UHR subjects, compared with controls, showed reduced cortical thickness in the right parahippocampal gyrus (p < 0.05, familywise error corrected). There were no significant differences in cortical thickness between the UHR subjects who later developed psychosis and those who did not. CONCLUSIONS: These data suggest that UHR symptomatology is characterized by alterations in the thickness of the medial temporal cortex. We did not find evidence that the later progression to psychosis was linked to additional alterations in cortical thickness, although we cannot exclude the possibility that the study lacked sufficient power to detect such differences.
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ItemNo Preview AvailableVolumetric Abnormalities Predating the Onset of Schizophrenia and Affective Psychoses: An MRI Study in Subjects at Ultrahigh Risk of Psychosis(OXFORD UNIV PRESS, 2012-09)It remains unclear whether brain structural abnormalities observed before the onset of psychosis are specific to schizophrenia or are common to all psychotic disorders. This study aimed to measure regional gray matter volume prior to the onset of schizophreniform and of affective psychoses. We investigated 102 subjects at ultrahigh risk (UHR) of developing psychosis recruited from the Personal Assessment and Crisis Evaluation Clinic in Melbourne, Australia. Twenty-eight of these subjects developed psychosis subsequent to scanning: 19 schizophrenia, 7 affective psychoses, and 2 other psychoses. We examined regional gray matter volume using 1.5 mm thick, coronal, 1.5 Tesla magnetic resonance imaging and voxel-based morphometry methods of image analysis. Subjects were scanned at presentation and were followed up clinically for a minimum of 12 months, to detect later transition to psychosis. We found that both groups of subjects who subsequently developed psychosis (schizophrenia and affective psychosis) showed reductions in the frontal cortex relative to UHR subjects who did not develop psychosis. The subgroup that subsequently developed schizophrenia also showed smaller volumes in the parietal cortex and, at trend level, in the temporal cortex, whereas those who developed an affective psychosis had significantly smaller subgenual cingulate volumes. These preliminary findings suggest that volumetric abnormalities in UHR individuals developing schizophrenia vs affective psychoses comprise a combination of features that predate both disorders and others that may be specific to the nature of the subsequent disorder.