Wide range of mental disorders increase the chance of suicidal thoughts and behaviors

Although depression is the mental disorder that most people associate with suicidal behavior, a new study reveals that a wide range of mental disorders increase the odds of thinking about suicide and making suicide attempts. Whereas depression is indeed one of the strongest predictors of suicidal thoughts across many different countries, it is disorders characterized by anxiety and poor impulse-control that best predict which people act on such thoughts—especially in developing countries, says a multi-country study published in this week's open access journal PLoS Medicine.

Using data from over 100,000 individuals in 21 countries participating in the WHO World Mental Health Surveys, Matthew Nock (Harvard University, Cambridge, Massachusetts, USA) and colleagues investigated which mental health disorders increase the odds of experiencing suicidal thoughts and actual suicide attempts, and how these relationships differ across developed and developing countries. The researchers collected and analyzed data on the lifetime presence and age-of-onset of mental disorders and of nonfatal suicidal behaviors using structured interviews.

While mental disorders are among the strongest known predictors of suicide, the multi-country study was initiated because people often have more than one mental disorder at a time and little is known about which disorders are uniquely predictive of suicidal behavior, the extent to which disorders predict suicide attempts beyond their association with suicidal thoughts, and whether these associations are similar across developed and developing countries, say the authors.

The authors found that mental disorders are present in approximately half of people who seriously consider killing themselves and two-thirds of those who make a suicide attempt. Overall, mental disorders were equally predictive of suicidal thoughts and attempts in developed and developing countries, with a key difference being that the strongest predictors of suicide attempts in developed countries were mood disorders, whereas in developing countries impulse-control, substance use, and post-traumatic stress disorders were most predictive

"These findings provide a more fine-grained understanding of the associations between mental disorders and subsequent suicidal behavior than previously available and indicate that mental disorders are predictive of suicidal behaviors in both developed and developing countries," say the authors, but "future research is needed to further delineate the mechanisms through which people come to think about suicide and subsequently progress from suicidal thoughts to attempts."

Funding: These activities were supported by the United States National Institute of Mental Health (R01MH077883; R01MH070884), the John D. and Catherine T.MacArthur Foundation, the Pfizer Foundation, the US Public Health Service (R13-MH066849, R01-MH069864, and R01DA016558), the Fogarty International Center (FIRCA R01-TW006481), the Pan American Health Organization, Eli Lilly and Company, Ortho-McNeil Pharmaceutical, GlaxoSmithKline, and Bristol-Myers Squibb. A complete list of WMH publications can be found at http://www.hcp.med.harvard.edu/wmh/. The Chinese World Mental Health Survey Initiative is supported by the Pfizer Foundation. The Colombian National Study of Mental Health (NSMH) is supported by the Ministry of Social Protection, with supplemental support from the Saldarriaga Concha Foundation. The ESEMeD project is funded by the European Commission (contracts QLG5-1999-01042; SANCO 2004123); the Piedmont Region (Italy); Fondo de I nvestigacion Sanitaria, Instituto de Salud Carlos III, Spain (FIS 00/0028); Ministerio de Ciencia y Tecnologı´a, Spain (SAF 2000-158-CE); Departament de Salut, Generalitat de Catalunya, Spain, RETICS RD06/0011 REM-TAP; and other local agencies, and by an unrestricted educational grant from GlaxoSmithKline. The Israel National Health Survey is funded by the Ministry of Health with support from the Israel National Institute for Health Policy and Health Services Research and the National Insurance Institute of Israel. The World Mental Health Japan (WMHJ) Survey is supported by the Grant for Research on Psychiatric and Neurological Diseases and Mental Health (H13-SHOGAI-023, H14-TOKUBETSU-026, H16-KOKORO-013) from the Japan Ministry of Health, Labour and Welfare. The Lebanese National Mental Health Survey (LNMHS) is supported by the Lebanese Ministry of Public Health; the WHO (Lebanon); the Fogarty International Center and anonymous private donations to IDRAAC, Lebanon; and unrestricted grants from Janssen Cilag, Eli Lilly, GlaxoSmithKline, Roche, and Novartis. The Mexican National Comorbidity Survey (MNCS) is supported by The National Institute of Psychiatry Ramon de la Fuente (INPRFMDIES 4280) and by the National Council on Science and Technology (CONACyT-G30544- H), with supplemental support from the PanAmerican Health Organization (PAHO). Te Rau Hinengaro: The New Zealand Mental Health Survey (NZMHS) is supported by the New Zealand Ministry of Health, Alcohol Advisory Council, and the Health Research Council. The Nigerian Survey of Mental Health and Wellbeing (NSMHW) is supported by the WHO (Geneva), the WHO (Nigeria), and the Federal Ministry of Health, Abuja, Nigeria. The South Africa Stress and Health Study (SASH) is supported by the US National Institute of Mental Health (R01-MH059575) and National Institute of Drug Abuse with supplemental funding from the Sout h African Department of Health and the University of Michigan. The Ukraine Comorbid Mental Disorders during Periods of Social Disruption (CMDPSD) study is funded by the US National Institute of Mental Health (RO1-MH61905). The US National Comorbidity Survey Replication (NCS-R) is supported by the National Institute of Mental Health (NIMH; U01-MH60220) with supplemental support from the National Institute of Drug Abuse (NIDA), the Substance Abuse and Mental Health Services Administration (SAMHSA), the Robert Wood Johnson Foundation (RWJF; Grant 044708), and the John W. Alden Trust. RCK, as principal investigator, had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests: With the exception of Ronald C Kessler no author has reported any competing interests. RCK has been a consultant for GlaxoSmithKline, Kaiser Permanente, Pfizer, Sanofi-Aventis, Shire Pharmaceuticals, and Wyeth-Ayerst; has served on advisory boards for Eli Lilly & Company and Wyeth-Ayerst; and has had research support for his epidemiological studies from Bristol-Myers Squibb, Eli Lilly & Company, GlaxoSmithKline, Johnson & Johnson Pharmaceuticals, Ortho-McNeil Pharmaceuticals, Pfizer, and Sanofi-Aventis.

Citation: Nock MK, Hwang I, Sampson N, Kessler RC, Angermeyer M, et al. (2009) Cross-National Analysis of the Associations among Mental Disorders and Suicidal Behavior: Findings from the WHO World Mental Health Surveys. PLoS Med 6(8): e1000123. doi:10.1371/journal.pmed.1000123

Editors' Summary: http://www.plos.org/press/plme-06-08-nock-summary.pdf

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CONTACT:
Matthew Nock
Harvard University
Department of Psychology
33 Kirkland Street, 1280
Cambridge, MA 02138
United States of America
+1 617 496-4484
+1 617-496-9462 (fax)
nock@wjh.harvard.edu

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