Centre for Youth Mental Health - Research Publications

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Author: Nelson, Christopher × Author: McGorry, Patrick × Start date: 2012 × End date: 2014 ×

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    Effects of NRG1 and DAOA genetic variation on transition to psychosis in individuals at ultra-high risk for psychosis
    Bousman, CA ; Yung, AR ; Pantelis, C ; Ellis, JA ; Chavez, RA ; Nelson, B ; Lin, A ; Wood, SJ ; Amminger, GP ; Velakoulis, D ; McGorry, PD ; Everall, IP ; Foley, DL (NATURE PUBLISHING GROUP, 2013-04)
    Prospective studies have suggested genetic variation in the neuregulin 1 (NRG1) and D-amino-acid oxidase activator (DAOA) genes may assist in differentiating high-risk individuals who will or will not transition to psychosis. In a prospective cohort (follow-up=2.4-14.9 years) of 225 individuals at ultra-high risk (UHR) for psychosis, we assessed haplotype-tagging single-nucleotide polymorphisms (htSNPs) spanning NRG1 and DAOA for their association with transition to psychosis, using Cox regression analysis. Two NRG1 htSNPs (rs12155594 and rs4281084) predicted transition to psychosis. Carriers of the rs12155594 T/T or T/C genotype had a 2.34 (95% confidence interval (CI)=1.37-4.00) times greater risk of transition compared with C/C carriers. For every rs4281084 A-allele the risk of transition increased by 1.55 (95% CI=1.05-2.27). For every additional rs4281084-A and/or rs12155594-T allele carried the risk increased ∼1.5-fold, with 71.4% of those carrying a combination of 3 of these alleles transitioning to psychosis. None of the assessed DAOA htSNPs were associated with transition. Our findings suggest NRG1 genetic variation may improve our ability to identify UHR individuals at risk for transition to psychosis.
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    Sexual Trauma Increases the Risk of Developing Psychosis in an Ultra High-Risk "Prodromal" Population
    Thompson, AD ; Nelson, B ; Yuen, HP ; Lin, A ; Amminger, GP ; McGorry, PD ; Wood, SJ ; Yung, AR (OXFORD UNIV PRESS, 2014-05)
    Studies indicate a high prevalence of childhood trauma in patient cohorts with established psychotic disorder and in those at risk of developing psychosis. A causal link between childhood trauma and development of psychosis has been proposed. We aimed to examine the association between experience of childhood trauma and the development of a psychotic disorder in a large "Ultra High Risk" (UHR) for psychosis cohort. The data were collected as part of a longitudinal cohort study of all UHR patients recruited to research studies at the Personal Assessment and Clinical Evaluation clinic between 1993 and 2006. Baseline data were collected at recruitment to these studies. The participants completed a comprehensive follow-up assessment battery (mean time to follow-up 7.5 years, range 2.4-14.9 years), which included the Childhood Trauma Questionnaire (CTQ), a self-report questionnaire that assesses experience of childhood trauma. The outcome of interest was transition to a psychotic disorder during the follow-up period. Data were available on 233 individuals. Total CTQ trauma score was not associated with transition to psychosis. Of the individual trauma types, only sexual abuse was associated with transition to psychosis (P = .02). The association remained when adjusting for potential confounding factors. Those with high sexual abuse scores were estimated to have a transition risk 2-4 times that of those with low scores. The findings suggest that sexual trauma may be an important contributing factor in development of psychosis for some individuals.
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    Phenylthiocarbamide (PTC) perception in ultra-high risk for psychosis participants who develop schizophrenia: Testing the evidence for an endophenotypic marker
    Brewer, WJ ; Lin, A ; Moberg, PJ ; Smutzer, G ; Nelson, B ; Yung, AR ; Pantelis, C ; McGorry, PD ; Turetsky, BI ; Wood, SJ (ELSEVIER IRELAND LTD, 2012-08-30)
    Reports suggesting that schizophrenia participants are more likely to be phenylthiocarbamide (PTC) non-tasters when compared to controls have recently been controversial. If supported, a genetic-based phenotypic variation in PTC taster status is implicated, suggesting a greater illness risk for those participants with recessive alleles for the TAS2R38 receptor. Should PTC insensitivity be a schizophrenia endophenotype, then it would be expected in follow-up of ultra high-risk for psychosis participants who later develop schizophrenia (UHR-S). UHR-S was hypothesised to show reduced PTC sensitivity compared to those who were previously at risk, but did not transition (UHR-NP). PTC perception was assessed in 219 UHR participants at long-term follow-up, of whom 53 had transitioned to psychosis (UHR-P) during the follow-up period. Fifteen of the 219 participants were diagnosed with schizophrenia. Seventy-eight had a family history of psychotic disorder. No differences in PTC taster status were found in UHR participants based upon transition to psychosis status, schizophrenia diagnosis, or family history of schizophrenia. This report indicates that schizophrenia development among UHR participants is not associated with PTC tasting deficits and fails to support previous findings that inability to detect the bitter taste of PTC is a schizophrenia endophenotype.
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    Omega-3 Fatty Acid Supplementation in Adolescents With Borderline Personality Disorder and Ultra-High Risk Criteria for Psychosis: A Post Hoc Subgroup Analysis of a Double-Blind, Randomized Controlled Trial
    Amminger, GP ; Chanen, AM ; Ohmann, S ; Klier, CM ; Mossaheb, N ; Bechdolf, A ; Nelson, B ; Thompson, A ; McGorry, PD ; Yung, AR ; Schaefer, MR (CANADIAN PSYCHIATRIC ASSOC, 2013-07)
    OBJECTIVE: To investigate whether long-chain omega-3 (n-3) polyunsaturated fatty acids (PUFAs) improve functioning and psychiatric symptoms in young people with borderline personality disorder (BPD) who also meet ultra-high risk criteria for psychosis. METHODS: We conducted a post hoc subgroup analysis of a double-blind, randomized controlled trial. Fifteen adolescents with BPD (mean age 16.2 years, [SD 2.1]) were randomized to either 1.2 g/day n-3 PUFAs or placebo. The intervention period was 12 weeks. Study measures included the Positive and Negative Syndrome Scale, the Montgomery-Åsberg Depression Rating Scale, and the Global Assessment of Functioning. Side effects were documented with the Udvalg for Kliniske Undersøgelser. Fatty acids in erythrocytes were analyzed using capillary gas chromatography. RESULTS: At baseline, erythrocyte n-3 PUFA levels correlated positively with psychosocial functioning and negatively with psychopathology. By the end of the intervention, n-3 PUFAs significantly improved functioning and reduced psychiatric symptoms, compared with placebo. Side effects did not differ between the treatment groups. CONCLUSIONS: Long-chain n-3 PUFAs should be further explored as a viable treatment strategy with minimal associated risk in young people with BPD. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00396643).