Skip to main content

Combined effects of physical illness and comorbid psychiatric disorder on risk of suicide in a national population study

  • Ping Qin (a1), Keith Hawton (a2), Preben Bo Mortensen (a3) and Roger Webb (a4)

People with physical illness often have psychiatric disorder and this comorbidity may have a specific influence on their risk of suicide.


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.


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.


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.


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.

Corresponding author
Professor Ping Qin, National Centre for Suicide Research and Prevention, Institute of Clinical Medicine, University of Oslo, Sognsvannsveien 21, N-0372 Oslo, Norway. Email:
Hide All

The study was funded by the Sygekassernes Helsefonden (National Health Insurance Foundation) in Denmark (2009B063). K.H. is a National (England) Institute of Research Senior Investigator.

Declaration of interest


Hide All
1 Dersh, J, Polatin, PB, Gatchel, RJ. Chronic pain and psychopathology: research findings and theoretical considerations. Psychosom Med 2002; 64: 773–86.
2 Koenig, HG, George, LK, Peterson, BL, Pieper, CF. Depression in medically ill hospitalized older adults: prevalence, characteristics, and course of symptoms according to six diagnostic schemes. Am J Psychiatry 1997; 154: 1376–83.
3 Moussavi, S, Chatterji, S, Verdes, E, Tandon, A, Patel, V, Ustun, B. Depression, chronic diseases, and decrements in health: results from the World Health Surveys. Lancet 2007; 370: 851–8.
4 Peveler, R, Carson, A, Rodin, G. Depression in medical patients. BMJ 2002; 325: 149–52.
5 Irving, G, Lloyd-Williams, M. Depression in advanced cancer. Eur J Oncol Nurs 2010; 14: 395–9.
6 Block, SD. Diagnosis and treatment of depression in patients with advanced illness. Epidemiol Psichiatr Soc 2010; 19: 103–9.
7 Allebeck, P, Bolund, C, Ringback, G. Increased suicide rate in cancer patients. A cohort study based on the Swedish Cancer-Environment Register. J Clin Epidemiol 1989; 42: 611–6.
8 Bronnum-Hansen, H, Stenager, E, Nylev, SE, Koch-Henriksen, N. Suicide among Danes with multiple sclerosis. J Neurol Neurosurg Psychiatry 2005; 76: 1457–9.
9 Larsen, KK, Agerbo, E, Christensen, B, Sondergaard, J, Vestergaard, M. Myocardial infarction and risk of suicide: a population-based case-control study. Circulation 2010; 122: 2388–93.
10 Qin, P, Mortensen, PB, Waltoft, BL, Postolache, TT. Allergy is associated with suicide completion with a possible mediating role of mood disorder – a population-based study. Allergy 2011; 66: 658–64.
11 Tseng, CH. Mortality and causes of death in a national sample of diabetic patients in Taiwan. Diabetes Care 2004; 27: 1605–9.
12 Cote, TR, Biggar, RJ, Dannenberg, AL. Risk of suicide among persons with AIDS. A national assessment. JAMA 1992; 268: 2066–8.
13 Webb, RT, Kontopantelis, E, Doran, T, Qin, P, Creed, F, Kapur, N. Suicide risk in primary care patients with major physical diseases: a case–control study. Arch Gen Psychiatry 2012; 69: 256–64.
14 Pirkis, J, Burgess, P. Suicide and recency of health care contacts. A systematic review. Br J Psychiatry 1998; 173: 462–74.
15 Hawton, K, van Heeringen, K. Suicide. Lancet 2009; 373: 1372–81.
16 Kaplan, MS, McFarland, BH, Huguet, N, Newsom, JT. Physical illness, functional limitations, and suicide risk: a population-based study. Am J Orthopsychiatry 2007; 77: 5660.
17 Qin, P, Webb, R, Kapur, N, Sorensen, HT. Hospitalization for physical illness and risk of subsequent suicide: a population study. J Intern Med 2013; 273: 4858.
18 Qin, P, Agerbo, E, Mortensen, PB. Suicide risk in relation to socioeconomic, demographic, psychiatric, and familial factors: a national register-based study of all suicides in Denmark, 1981–1997. Am J Psychiatry 2003; 160: 765–72.
19 Qin, P, Agerbo, E, Mortensen, PB. Factors contributing to suicide: the epidemiological evidence from large-scale registers. In Prevention and Treatment of Suicidal Behaviour: From Science to Practice (ed. Hawton, K): 1128. Oxford University Press, 2005.
20 Laursen, TM, Munk-Olsen, T, Gasse, C. Chronic somatic comorbidity and excess mortality due to natural causes in persons with schizophrenia or bipolar affective disorder. PLoS One 2011; 6: e24597.
21 Dixon, L, Postrado, L, Delahanty, J, Fischer, PJ, Lehman, A. The association of medical comorbidity in schizophrenia with poor physical and mental health. J Nerv Ment Dis 1999; 187: 496502.
22 Goodwin, RD, Marusic, A, Hoven, CW. Suicide attempts in the United States: the role of physical illness. Soc Sci Med 2003; 56: 1783–8.
23 Pedersen, CB, Gotzsche, H, Moller, JO, Mortensen, PB. The Danish Civil Registration System. A cohort of eight million persons. Dan Med Bull 2006; 53: 441–9.
24 Juel, K, Helweg-Larsen, K. The Danish registers of causes of death. Dan Med Bull 1999; 46: 354–7.
25 World Health Organization. The International Classification of Diseases, Eighth Revision (ICD-8). WHO, 1965.
26 World Health Organization. The International Classification of Diseases, Tenth Revision (ICD-10). WHO, 1990.
27 Statistik, D. IDA – en integreret database for arbejdsmarkedsforskning. Danmarks Statistiks trykkeri, 1991.
28 Clayton, D, Hills, M. Statistical Models in Epidemiology. Oxford University Press, 1993.
29 Andersen, TF, Madsen, M, Jorgensen, J, Mellemkjoer, L, Olsen, JH. The Danish National Hospital Register. A valuable source of data for modern health sciences. Dan Med Bull 1999; 46: 263–8.
30 Munk-Jorgensen, P, Mortensen, PB. The Danish Psychiatric Central Register. Dan Med Bull 1997; 44: 82–4.
31 Agerbo, E, Byrne, M, Eaton, WW, Mortensen, PB. Marital and labor market status in the long run in schizophrenia. Arch Gen Psychiatry 2004; 61: 2833.
32 SAS Institute. The PHREG Procedure. In SAS/STAT9(R) 9.2 User's Guide, Second Edition. SAS Institute, 2013 (
33 King, G, Zeng, L. Estimating risk and rate levels, ratios and differences in case–control studies. Stat Med 2002; 21: 1409–27.
34 Watson, D, Pennebaker, JW. Health complaints, stress, and distress: exploring the central role of negative affectivity. Psychol Rev 1989; 96: 234–54.
35 Evans, DL, Charney, DS, Lewis, L, Golden, RN, Gorman, JM, Krishnan, KR, et al. Mood disorders in the medically ill: scientific review and recommendations. Biol Psychiatry 2005; 58: 175–89.
36 Joiner, TE Jr, Van Orden, KA, Witte, TK, Selby, EA, Ribeiro, JD, Lewis, R, et al. Main predictions of the interpersonal-psychological theory of suicidal behavior: empirical tests in two samples of young adults. J Abnorm Psychol 2009; 118: 634–46.
37 Ribeiro, JD, Joiner, TE. The interpersonal-psychological theory of suicidal behavior: current status and future directions. J Clin Psychol 2009; 65: 1291–9.
38 Pirkola, S, Saarni, S, Suvisaari, J, Elovainio, M, Partonen, T, Aalto, AM, et al. General health and quality-of-life measures in active, recent, and comorbid mental disorders: a population-based health 2000 study. Compr Psychiatry 2009; 50: 108–14.
39 Baumeister, H, Balke, K, Harter, M. Psychiatric and somatic comorbidities are negatively associated with quality of life in physically ill patients. J Clin Epidemiol 2005; 58: 1090–100.
40 von Ammon, CS, Furlanetto, LM, Creech, SD, Powell, LH. Medical illness, past depression, and present depression: a predictive triad for in-hospital mortality. Am J Psychiatry 2001; 158: 43–8.
41 Leucht, S, Burkard, T, Henderson, J, Maj, M, Sartorius, N. Physical illness and schizophrenia: a review of the literature. Acta Psychiatr Scand 2007; 116: 317–33.
42 Bazalgette, L, Bradley, W, Ousbey, J. The Truth About Suicide. DEMOS, 2012.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

The British Journal of Psychiatry
  • ISSN: 0007-1250
  • EISSN: 1472-1465
  • URL: /core/journals/the-british-journal-of-psychiatry
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 21 *
Loading metrics...

Abstract views

Total abstract views: 45 *
Loading metrics...

* Views captured on Cambridge Core between 3rd January 2018 - 21st March 2018. This data will be updated every 24 hours.

Combined effects of physical illness and comorbid psychiatric disorder on risk of suicide in a national population study

  • Ping Qin (a1), Keith Hawton (a2), Preben Bo Mortensen (a3) and Roger Webb (a4)
Submit a response


No eLetters have been published for this article.


Reply to: Submit a response

Your details

Conflicting interests

Do you have any conflicting interests? *