B Nelson1, H P Yuen2, A Lin3, S J Wood4, P D McGorry2, J A Hartmann2, A R Yung5. 1. Orygen, The National Centre of Excellence in Youth Mental Health, University of Melbourne, Victoria, Australia. Electronic address: Barnaby.Nelson@orygen.org.au. 2. Orygen, The National Centre of Excellence in Youth Mental Health, University of Melbourne, Victoria, Australia. 3. Telethon Kids Institute, The University of Western Australia, Australia. 4. School of Psychology, University of Birmingham, Birmingham, UK. 5. Institute of Brain, Behaviour and Mental Health, University of Manchester, Manchester, UK.
Abstract
BACKGROUND: The rate of transition to psychotic disorder in ultra high risk (UHR) patients has declined in recent cohorts. The reasons for this are unclear, but may include a lead-time bias, earlier intervention, a change in clinical characteristics of cohorts, and treatment changes. AIMS: In this paper we examined the two possibilities related to reduction in duration of symptoms prior to clinic entry, i.e., lead-time bias and earlier intervention. METHOD: The sample consisted of all UHR research participants seen at the PACE clinic, Melbourne between 1993 and 2006 (N=416), followed for a mean of 7.5years (the 'PACE 400' cohort). Duration of symptoms was analysed by four baseline year time periods. Analysis of transition rate by duration of symptoms was restricted to more homogenous sub-samples (pre-1998 and pre-2001) in order to minimize confounding effects of change in patient characteristics or treatments. These cohorts were divided into those with a short and long duration of symptoms using a cut-point approach. RESULTS: Duration of symptoms prior to entry did not reduce significantly between 1993 and 2006 (p=0.10). The group with a short duration of symptoms showed lower transition rates and did not catch up in transition rate compared to the long duration of symptoms group. DISCUSSION: These data suggest that, while earlier intervention or lead-time bias do not fully account for the declining transition rate in UHR cohorts, it appears that earlier intervention may have exerted a stronger influence on this decline than length of follow-up period (lead-time bias).
BACKGROUND: The rate of transition to psychotic disorder in ultra high risk (UHR) patients has declined in recent cohorts. The reasons for this are unclear, but may include a lead-time bias, earlier intervention, a change in clinical characteristics of cohorts, and treatment changes. AIMS: In this paper we examined the two possibilities related to reduction in duration of symptoms prior to clinic entry, i.e., lead-time bias and earlier intervention. METHOD: The sample consisted of all UHR research participants seen at the PACE clinic, Melbourne between 1993 and 2006 (N=416), followed for a mean of 7.5years (the 'PACE 400' cohort). Duration of symptoms was analysed by four baseline year time periods. Analysis of transition rate by duration of symptoms was restricted to more homogenous sub-samples (pre-1998 and pre-2001) in order to minimize confounding effects of change in patient characteristics or treatments. These cohorts were divided into those with a short and long duration of symptoms using a cut-point approach. RESULTS: Duration of symptoms prior to entry did not reduce significantly between 1993 and 2006 (p=0.10). The group with a short duration of symptoms showed lower transition rates and did not catch up in transition rate compared to the long duration of symptoms group. DISCUSSION: These data suggest that, while earlier intervention or lead-time bias do not fully account for the declining transition rate in UHR cohorts, it appears that earlier intervention may have exerted a stronger influence on this decline than length of follow-up period (lead-time bias).
Authors: Barnaby Nelson; G Paul Amminger; Hok Pan Yuen; Nicky Wallis; Melissa J Kerr; Lisa Dixon; Cameron Carter; Rachel Loewy; Tara A Niendam; Martha Shumway; Sarah Morris; Julie Blasioli; Patrick D McGorry Journal: Early Interv Psychiatry Date: 2017-07-18 Impact factor: 2.732
Authors: Ya Wang; Esmee E Braam; Cassandra M J Wannan; Tamsyn E Van Rheenen; Raymond C K Chan; Barnaby Nelson; Patrick D McGorry; Alison R Yung; Ashleigh Lin; Warrick J Brewer; John Koutsogiannis; Stephen J Wood; Dennis Velakoulis; Christos Pantelis; Vanessa L Cropley Journal: Eur Arch Psychiatry Clin Neurosci Date: 2021-08-31 Impact factor: 5.270
Authors: B Nelson; G P Amminger; H P Yuen; C Markulev; S Lavoie; M R Schäfer; J A Hartmann; N Mossaheb; M Schlögelhofer; S Smesny; I B Hickie; G Berger; E Y H Chen; L de Haan; D H Nieman; M Nordentoft; A Riecher-Rössler; S Verma; A Thompson; A R Yung; P D McGorry Journal: NPJ Schizophr Date: 2018-06-25
Authors: Lorna Staines; Ruchika Gajwani; Joachim Gross; Andrew I Gumley; Stephen M Lawrie; Matthias Schwannauer; Frauke Schultze-Lutter; Peter J Uhlhaas Journal: BMC Psychiatry Date: 2021-07-07 Impact factor: 3.630
Authors: Barnaby Nelson; G Paul Amminger; Andrew Thompson; Stephen J Wood; Alison R Yung; Patrick D McGorry Journal: Front Psychiatry Date: 2020-05-27 Impact factor: 4.157
Authors: C Wenneberg; B Y Glenthøj; L B Glenthøj; B Fagerlund; K Krakauer; T D Kristensen; C Hjorthøj; R A E Edden; B V Broberg; K B Bojesen; E Rostrup; M Nordentoft Journal: Eur Psychiatry Date: 2020-08-07 Impact factor: 5.361
Authors: I Paetzold; I Myin-Germeys; A Schick; B Nelson; E Velthorst; F Schirmbeck; J van Os; C Morgan; J Hartmann; M van der Gaag; L de Haan; L Valmaggia; P McGuire; M Kempton; U Reininghaus Journal: Epidemiol Psychiatr Sci Date: 2021-05-28 Impact factor: 6.892