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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). [ABSTRACT FROM AUTHOR]

Clinical trials for the treatment of schizophrenia now often include cognitive assessments in addition to clinical ratings of symptoms. Recently, these trials have included cross-national assessments. It is not clear if translated psychological tests produce consistent results across different languages. This paper presents the results of a study of the comparability of the results of cognitive assessments in different English-speaking countries and a number of countries where tests were translated into other languages. Performance on tests of executive functioning, verbal and visuo-spatial learning and memory, language skills, psychomotor speed, and vigilance was compared across the first episode patients with schizophrenia (n=301) assessed in six different languages (English, French, Finnish, German, Hebrew, and Afrikaans), including two different countries where patients were assessed in English and other languages: Canada (French) and South Africa (Afrikaans). The variance in performance across the sites tested in English was as large as the variance between English and non-English speakers when all tests were considered. Performance differences across English and other languages were found only for executive functions, vigilance, and psychomotor speed, with executive functioning differences nonsignificant when education was considered. No differences were found between English and non-English speakers in Canada. These results suggest that the translation of tests of memory and verbal skills can lead to consistent results across translated versions of the tests. Differences between countries were greater than differences between languages, suggesting the need to consider representativeness of patient samples in terms of local educational attainment. In general, these data support the validity of cross-national neuropsychological assessments. [Copyright &y& Elsevier]