title: Predicting onset of major depression in general practice attendees in Europe: extending the application of the predictD risk algorithm from 12 to 24 months.
abstract: BACKGROUND
  PredictD is a risk algorithm that was developed to predict risk of onset of major depression over 12 months in general practice attendees in Europe and validated in a similar population in Chile. It was the first risk algorithm to be developed in the field of mental disorders. Our objective was to extend predictD as an algorithm to detect people at risk of major depression over 24 months. Method Participants were 4190 adult attendees to general practices in the UK, Spain, Slovenia and Portugal, who were not depressed at baseline and were followed up for 24 months. The original predictD risk algorithm for onset of DSM-IV major depression had already been developed in data arising from the first 12 months of follow-up. In this analysis we fitted predictD to the longer period of follow-up, first by examining only the second year (12-24 months) and then the whole period of follow-up (0-24 months).
  
  
  RESULTS
  The instrument performed well for prediction of major depression from 12 to 24 months [c-index 0.728, 95% confidence interval (CI) 0.675-0.781], or over the whole 24 months (c-index 0.783, 95% CI 0.757-0.809).
  
  
  CONCLUSIONS
  The predictD risk algorithm for major depression is accurate over 24 months, extending it current use of prediction over 12 months. This strengthens its use in prevention efforts in general medical settings.
authors.affiliation: Mental Health Sciences Unit, Faculty of Brain Sciences, University College London Medical School, London, UK. michael.king@ucl.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: King
authors.forename: C
authors.initials: C
authors.lastname: Bottomley
authors.forename: J
authors.initials: J
authors.lastname: Bellón-Saameño
authors.forename: F
authors.initials: F
authors.lastname: Torres-Gonzalez
authors.forename: I
authors.initials: I
authors.lastname: Svab
authors.forename: D
authors.initials: D
authors.lastname: Rotar
authors.forename: M
authors.initials: M
authors.lastname: Xavier
authors.forename: I
authors.initials: I
authors.lastname: Nazareth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D058006:General Practice; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods*; D017524:Slovenia / Q000453:epidemiology; D013030:Spain / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult