title: Derivation of a prediction model for a diagnosis of depression in young adults: a matched case-control study using electronic primary care records.
abstract: Approximately 80 000 children and young people in the UK suffer from depression, but many are untreated because of poor identification of early warning signs and risk factors.
  
  
  
  This study aimed to derive and to investigate discrimination characteristics of a prediction model for a first recorded diagnosis of depression in young people aged 15-24 years.
  
  
  
  This study used a matched case-control method using electronic primary care records. Stepwise conditional logistic regression modelling investigated 42 potential predictors including symptoms, co-morbidities, social factors and drug and alcohol misuse.
  
  
  
  Of the socio-economic and symptomatic predictors identified, the strongest associations were with depression symptoms and other psychological conditions. School problems and social services involvement were prominent predictors in men aged 15-18 years, work stress in women aged 19-24 years.
  
  
  
  Our model is a first step in the development of a predictive model identifying early warning signs of depression in young people in primary care.
authors.affiliation: Primary Care Clinical Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Linda
authors.initials: L
authors.lastname: Nichols
authors.affiliation: Primary Care Clinical Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Ronan
authors.initials: R
authors.lastname: Ryan
authors.affiliation: Centre for Mental Health, Birmingham and Solihull Mental Health NHS Foundation Trust, Birmingham, UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Connor
authors.affiliation: WMS - Mental Health and Wellbeing, University of Warwick, Coventry, UK.
authors.forename: Max
authors.initials: M
authors.lastname: Birchwood
authors.affiliation: Primary Care Clinical Sciences, University of Birmingham, Birmingham, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Marshall
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016022:Case-Control Studies; D003863:Depression / Q000150:complications / Q000175:diagnosis*; D042241:Early Diagnosis; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008960:Models, Psychological; D011320:Primary Health Care; D062706:Prodromal Symptoms; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
keywords: depression; primary care; young adults