title: Combined effects of physical illness and comorbid psychiatric disorder on risk of suicide in a national population study.
abstract: BACKGROUND
  People with physical illness often have psychiatric disorder and this comorbidity may have a specific influence on their risk of suicide.
  
  
  OBJECTIVE
  To examine how physical illness and psychiatric comorbidity interact to influence risk of suicide, with particular focus on relative timing of onset of the two types of illness.
  
  
  METHODS
  Based on the national population of Denmark, individual-level data were retrieved from five national registers on 27 262 suicide cases and 468 007 gender- and birth-date matched living controls. Data were analysed using conditional logistic regression.
  
  
  RESULTS
  Both suicides and controls with physical illness more often had comorbid psychiatric disorder than their physically healthy counterparts. Although both physical and psychiatric illnesses constituted significant risk factors for suicide, their relative timing of onset in individuals with comorbidity significantly differentiated the associated risk of suicide. While suicide risk was highly elevated when onsets of both physical and psychiatric illness occurred close in time to each other, regardless which came first, psychiatric comorbidity developed some time after onset of physical illness exacerbated the risk of suicide substantially.
  
  
  CONCLUSIONS
  Suicide risk in physically ill people varies substantially by presence of psychiatric comorbidity, particularly the relative timing of onset of the two types of illness. Closer collaboration between general and mental health services should be an essential component of suicide prevention strategies.
authors.affiliation: Ping Qin, MD, PhD, National Centre for Register-based Research, Aarhus University, Denmark, and National Centre for Suicide Research and Prevention, Institute of Clinical Medicine, University of Oslo, Norway; Keith Hawton, DSc, DM, Centre for Suicide Study, Department of Psychiatry, Oxford University, UK; Preben Bo Mortensen, MD, DrMedSc, National Centre for Register-based Research, Aarhus University, Denmark; Roger Webb, MSc, PhD, Centre for Mental Health and Risk, University of Manchester, UK.
authors.forename: Ping
authors.initials: P
authors.lastname: Qin
authors.affiliation: Ping Qin, MD, PhD, National Centre for Register-based Research, Aarhus University, Denmark, and National Centre for Suicide Research and Prevention, Institute of Clinical Medicine, University of Oslo, Norway; Keith Hawton, DSc, DM, Centre for Suicide Study, Department of Psychiatry, Oxford University, UK; Preben Bo Mortensen, MD, DrMedSc, National Centre for Register-based Research, Aarhus University, Denmark; Roger Webb, MSc, PhD, Centre for Mental Health and Risk, University of Manchester, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Hawton
authors.affiliation: Ping Qin, MD, PhD, National Centre for Register-based Research, Aarhus University, Denmark, and National Centre for Suicide Research and Prevention, Institute of Clinical Medicine, University of Oslo, Norway; Keith Hawton, DSc, DM, Centre for Suicide Study, Department of Psychiatry, Oxford University, UK; Preben Bo Mortensen, MD, DrMedSc, National Centre for Register-based Research, Aarhus University, Denmark; Roger Webb, MSc, PhD, Centre for Mental Health and Risk, University of Manchester, UK.
authors.forename: Preben Bo
authors.initials: PB
authors.lastname: Mortensen
authors.affiliation: Ping Qin, MD, PhD, National Centre for Register-based Research, Aarhus University, Denmark, and National Centre for Suicide Research and Prevention, Institute of Clinical Medicine, University of Oslo, Norway; Keith Hawton, DSc, DM, Centre for Suicide Study, Department of Psychiatry, Oxford University, UK; Preben Bo Mortensen, MD, DrMedSc, National Centre for Register-based Research, Aarhus University, Denmark; Roger Webb, MSc, PhD, Centre for Mental Health and Risk, University of Manchester, UK.
authors.forename: Roger
authors.initials: R
authors.lastname: Webb
mesh_terms: D016022:Case-Control Studies; D015897:Comorbidity; D016208:Databases, Factual; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology*; D012307:Risk Factors; D017678:Sex Distribution; D013405:Suicide / Q000706:statistics & numerical data*