Melbourne School of Psychological Sciences - Research Publications
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ItemNo Preview AvailableThe relationship between subjective sleep disturbance and attenuated psychotic symptoms after accounting for anxiety and depressive symptoms(ELSEVIER, 2023-08)BACKGROUND AND HYPOTHESES: Sleep disturbances are increasingly recognized as cooccurring with psychotic symptoms. The potential importance of this relationship is complicated when considering the effects of anxiety and depressive symptoms which commonly present in early-stage illness states. This study aimed to investigate the relationship between self-reported sleep disturbance on the development of attenuated psychotic symptoms (APS) cross-sectionally and longitudinally while adjusting for roles of anxiety and depressive symptoms. DESIGN: Eight-hundred and two help-seeking young people aged 12 to 25 years who engaged with our Australian early intervention services were included in the study (the "Transitions" cohort). Cross sectional mediation and cross-lagged longitudinal (12-month) mediation models were developed with outcomes being different APS domains. RESULTS: Only baseline excessive daytime sleepiness predicted later APS when accounting for previous APS, anxiety and depressive symptomatology. Cross sectionally, self-reported sleep disturbance showed both direct and indirect predictive relationships with all APS domains. Partial mediation through anxiety and depression was shown for unusual thought content, perceptual abnormalities, and disorganised speech, while full mediation through depression was shown for non-bizarre ideas. CONCLUSIONS: The specificity of the relationship between self-reported sleep disturbance on APS highlights the potential for different roles in mechanistic models of psychotic symptom expression. This further indicates the need for further experimental research to illuminate potential causal pathways. Future research should continue to use continuous, symptom level approaches across a range of timeframes to more accurately model the complex dynamics present in the sleep-psychosis relationship.
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ItemNo Preview AvailableChildhood trauma is prevalent and associated with co-occurring depression, anxiety, mania and psychosis in young people attending Australian youth mental health services(SAGE PUBLICATIONS LTD, 2023-12)OBJECTIVES: Childhood trauma is common and associated with mental ill health. While high rates of trauma are observed across individual disorders, there is evidence that trauma is associated with an admixture of affective, anxiety and psychotic symptoms in adults. Given that early onset of mental disorder and trauma exposure herald poor outcomes, it is important to examine trauma prevalence rates in youth mental health services and to determine whether this trauma-related clustering is present in help-seeking young people. METHODS: We used data from the Transitions Study, a longitudinal investigation of young people attending headspace youth mental health services in Australia between January 2011 and August 2012. Participants were 775 young people aged 12-25. Childhood trauma was assessed using the Childhood Trauma Questionnaire. Multinomial regression was used to assess whether reported childhood trauma was more strongly associated with the co-occurrence of depression, anxiety, mania and psychosis symptoms than with any one in isolation. RESULTS: Approximately 84% of participants reported some form of abuse (emotional: 68%; physical: 32%; sexual: 22%) or neglect (emotional: 65%; physical: 46%). Exposure to multiple trauma types was common. Childhood trauma was significantly associated with each symptom domain. More severe childhood trauma was more strongly associated with the co-occurrence of symptoms than with any one symptom domain in isolation, such that more severely trauma-exposed young people were more likely to experience increased symptom clustering. CONCLUSIONS: Childhood trauma is pervasive in youth mental health services and associated with a symptom profile that cuts across traditional diagnostic boundaries.
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ItemNo Preview AvailableIntelligence trajectories in individuals at ultra-high risk for psychosis: An 8-year longitudinal analysis(ELSEVIER, 2022-10)Cognitive impairment is a well-documented predictor of transition to a full-threshold psychotic disorder amongst individuals at ultra-high risk (UHR) for psychosis. However, less is known about whether change in cognitive functioning differs between those who do and do not transition. Studies to date have not examined trajectories in intelligence constructs (e.g., acquired knowledge and fluid intelligence), which have demonstrated marked impairments in individuals with schizophrenia. This study aimed to examine intelligence trajectories using longitudinal data spanning an average of eight years, where some participants completed assessments over three time-points. Participants (N = 139) at UHR for psychosis completed the Wechsler Abbreviated Scale of Intelligence (WASI) at each follow-up. Linear mixed-effects models mapped changes in WASI Full-Scale IQ (FSIQ) and T-scores on Vocabulary, Similarities, Block Design, and Matrix Reasoning subtests. The sample showed stable and improving trajectories for FSIQ and all subtests. There were no significant differences in trajectories between those who did and did not transition to psychosis and between individuals with good and poor functional outcomes. However, although not significant, the trajectories of the acquired knowledge subtests diverged between transitioned and non-transitioned individuals (β = -0.12, 95 % CI [-0.29, 0.05] for Vocabulary and β = -0.14, 95 % CI [-0.33, 0.05] for Similarities). Overall, there was no evidence for long-term deterioration in intelligence trajectories in this UHR sample. Future studies with a larger sample of transitioned participants may be needed to explore potential differences in intelligence trajectories between UHR transition groups and other non-psychosis outcomes.
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ItemNo Preview AvailablePineal morphology of the clinical high-risk state for psychosis and different psychotic disorders(ELSEVIER, 2022-06)BACKGROUND: Pineal volume reductions have been reported in schizophrenia and clinical high-risk states for the development of psychosis, supporting the role of melatonin dysregulation in the pathophysiology of psychosis. However, it remains unclear whether pineal volume is associated with the later onset of psychosis in individuals at clinical high-risk (CHR) of psychosis or if pineal atrophy is specific to schizophrenia among different psychotic disorders. METHODS: This magnetic resonance imaging study examined the volume of and cyst prevalence in the pineal gland in 135 individuals at CHR of psychosis [52 (38.5%) subsequently developed psychosis], 162 with first-episode psychosis (FEP), 89 with chronic schizophrenia, and 87 healthy controls. The potential contribution of the pineal morphology to clinical characteristics was also examined in the CHR and FEP groups. RESULTS: Pineal volumes did not differ significantly between the CHR, FEP, and chronic schizophrenia groups, but were significantly smaller than that in healthy controls. However, pineal volumes were not associated with the later onset of psychosis in the CHR group or FEP sub-diagnosis (i.e., schizophrenia, schizophreniform disorder, affective psychosis, and other psychoses). No significant differences were observed in the prevalence of pineal cysts between the groups, and it also did not correlate with clinical characteristics in the CHR and FEP groups. CONCLUSION: These results suggest that pineal atrophy is a general vulnerability marker of psychosis, while pineal cysts do not appear to contribute to the pathophysiology of psychosis.
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ItemAripiprazole compared with placebo for auditory verbal hallucinations in youth with borderline personality disorder: Protocol for the VERBATIM randomized controlled trial(WILEY, 2019-12)AIM: Up to half of patients with borderline personality disorder report auditory verbal hallucinations that are phenomenologically indistinguishable from those in schizophrenia, occur early in the course of the disorder, and are enduring, distressing and disabling. In clinical practice, this symptom is widely assumed to be unresponsive to treatment with antipsychotic medication and early intervention is rarely offered. The Verbal Experiences Response in Borderline personality disorder to Aripiprazole TrIal Medication (VERBATIM) study aims to be the first controlled trial to investigate the effectiveness of conventional pharmacotherapy for this symptom in this patient group. METHOD: VERBATIM is a 12-week, triple-blind, single-centre, parallel groups randomised controlled trial, with a 27-week follow-up period. Participants between the ages of 15 and 25 years receive either aripiprazole or placebo daily, commencing at 2 mg and increasing to 10 mg by day 15. Further dose escalations (up to 30 mg) may occur, as clinically indicated. This trial was prospectively registered with the Australian and New Zealand Clinical Trials Registry ACTRN12616001192471 on 30/08/2016. RESULTS: The primary outcome is severity of auditory verbal hallucinations assessed using the Psychotic Symptom Rating Scale. Secondary outcomes include the severity of general psychopathology, borderline personality pathology, social and occupational functioning and change in brain resting state connectivity. The primary endpoint is week 12 and secondary endpoint is week 39. CONCLUSION: The results will inform treatment decisions for individuals with borderline personality disorder who present with auditory verbal hallucinations.
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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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ItemCognitive ability and metabolic physical health in first-episode psychosis(ELSEVIER, 2021-06)Cognitive impairments are a core feature of first-episode psychosis (FEP), arising before illness onset and antipsychotic exposure. Individuals with chronic psychosis experience poorer physical health while taking antipsychotic medication, but health disparities may be evident at FEP onset, prior to antipsychotic exposure. Given the links between cognition and physical health in healthy populations, the aim was to explore whether cognition and physical health are associated in FEP, which could inform early physical health interventions for cognition in FEP. Participants were aged 15 to 25 and included 86 individuals experiencing FEP with limited antipsychotic exposure and duration of untreated psychosis of ≤six months, and 43 age- and sex-matched controls. Individuals with FEP performed significantly poorer than controls in most cognitive domains (Cohen's d = 0.38 to 1.59). Groups were similar in metabolic health measures, excluding a significantly faster heart rate in FEP (d = 0.68). Through hierarchical regression analyses, we found that in the overall sample, BMI was negatively related to current IQ after controlling for education and group (FEP/control). Relationships between BMI and cognition were consistent across the FEP and healthy control groups. In FEP, current IQ and working memory were negatively correlated with lipid profiles. Findings suggest that in FEP, impaired cognition is exhibited earlier than physical health problems, and that compared to controls, similar relationships with cognition are demonstrated. Causal pathways and trajectories of relationships between health and cognition in FEP require investigation, especially as antipsychotic medications are introduced. The findings have implications for cognitive and health interventions.
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ItemNo Preview AvailableCan antipsychotic dose reduction lead to better functional recovery in first-episode psychosis? A randomized controlled-trial of antipsychotic dose reduction. The reduce trial: Study protocol(WILEY, 2019-12)UNLABELLED: Antipsychotic medication has been the mainstay of treatment for psychotic illnesses for over 60 years. This has been associated with improvements in positive psychotic symptoms and a reduction in relapse rates. However, there has been little improvement in functional outcomes for people with psychosis. At the same time there is increasing evidence that medications contribute to life shortening metabolic and cardiovascular illnesses. There is also uncertainty as to the role played by antipsychotic medication in brain volume changes. AIM: The primary aim of the study is, in a population of young people with first-episode psychosis, to compare functional outcomes between an antipsychotic dose reduction strategy with evidence-based intensive recovery treatment (EBIRT) group (DRS+) and an antipsychotic maintenance treatment with EBIRT group (AMTx+) at 24-months follow-up. METHODS: Our single-blind randomized controlled trial, within a specialist early psychosis treatment setting, will test the whether the DRS+ group leads to better vocational and social recovery than, the AMTx+ group over a 2-year period in 180 remitted first-episode psychosis patients. Additionally, we will examine the effect of DRS+ vs AMTx+ on physical health, brain volume and cognitive functioning. This study will also determine whether the group receiving DRS+ will be no worse off in terms of psychotic relapses over 2 years follow-up. RESULTS: This paper presents the protocol, rationale and hypotheses for this study which commenced recruitment in July 2017. CONCLUSION: This study will provide evidence as to whether an antipsychotic dose-reduction recovery treatment leads to improved functioning and safer outcomes in first-episode psychosis patients. In addition, it will be the first-controlled experiment of the effect of exposure to antipsychotic maintenance treatment on brain volume changes in this population.
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ItemNo Preview AvailableThe Impact of Cannabis Use on Cognitive Functioning in Patients With Schizophrenia: A Meta-analysis of Existing Findings and New Data in a First-Episode Sample(OXFORD UNIV PRESS, 2012-03)Cannabis use is highly prevalent among people with schizophrenia, and coupled with impaired cognition, is thought to heighten the risk of illness onset. However, while heavy cannabis use has been associated with cognitive deficits in long-term users, studies among patients with schizophrenia have been contradictory. This article consists of 2 studies. In Study I, a meta-analysis of 10 studies comprising 572 patients with established schizophrenia (with and without comorbid cannabis use) was conducted. Patients with a history of cannabis use were found to have superior neuropsychological functioning. This finding was largely driven by studies that included patients with a lifetime history of cannabis use rather than current or recent use. In Study II, we examined the neuropsychological performance of 85 patients with first-episode psychosis (FEP) and 43 healthy nonusing controls. Relative to controls, FEP patients with a history of cannabis use (FEP + CANN; n = 59) displayed only selective neuropsychological impairments while those without a history (FEP - CANN; n = 26) displayed generalized deficits. When directly compared, FEP + CANN patients performed better on tests of visual memory, working memory, and executive functioning. Patients with early onset cannabis use had less neuropsychological impairment than patients with later onset use. Together, these findings suggest that patients with schizophrenia or FEP with a history of cannabis use have superior neuropsychological functioning compared with nonusing patients. This association between better cognitive performance and cannabis use in schizophrenia may be driven by a subgroup of "neurocognitively less impaired" patients, who only developed psychosis after a relatively early initiation into cannabis use.
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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.