Cross-national analysis of the associations among mental disorders and suicidal behavior: findings from the WHO World Mental Health Surveys.
BACKGROUND
Suicide is a leading cause of death worldwide. Mental disorders are among the strongest predictors of suicide; however, 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. This study was designed to test each of these questions with a focus on nonfatal suicide attempts.


RESULTS
Data on the lifetime presence and age-of-onset of Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) mental disorders and nonfatal suicidal behaviors were collected via structured face-to-face interviews with 108,664 respondents from 21 countries participating in the WHO World Mental Health Surveys. The results show that each lifetime disorder examined significantly predicts the subsequent first onset of suicide attempt (odds ratios [ORs] = 2.9-8.9). After controlling for comorbidity, these associations decreased substantially (ORs = 1.5-5.6) but remained significant in most cases. Overall, mental disorders were equally predictive 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. Disaggregation of the associations between mental disorders and nonfatal suicide attempts showed that these associations are largely due to disorders predicting the onset of suicidal thoughts rather than predicting progression from thoughts to attempts. In the few instances where mental disorders predicted the transition from suicidal thoughts to attempts, the significant disorders are characterized by anxiety and poor impulse-control. The limitations of this study include the use of retrospective self-reports of lifetime occurrence and age-of-onset of mental disorders and suicidal behaviors, as well as the narrow focus on mental disorders as predictors of nonfatal suicidal behaviors, each of which must be addressed in future studies.


CONCLUSIONS
This study found that a wide range of mental disorders increased the odds of experiencing suicide ideation. However, after controlling for psychiatric comorbidity, only disorders characterized by anxiety and poor impulse-control predict which people with suicide ideation act on such thoughts. 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 predict suicidal behaviors similarly in both developed and developing countries. Future research is needed to delineate the mechanisms through which people come to think about suicide and subsequently progress from ideation to attempts.
Nock
Matthew K
MK
Department of Psychology, Harvard University, Cambridge, Massachusetts, USA. nock@wjh.harvard.edu
Hwang
Irving
I
Sampson
Nancy
N
Kessler
Ronald C
RC
Angermeyer
Matthias
M
Beautrais
Annette
A
Borges
Guilherme
G
Bromet
Evelyn
E
Bruffaerts
Ronny
R
de Girolamo
Giovanni
G
de Graaf
Ron
R
Florescu
Silvia
S
Gureje
Oye
O
Haro
Josep Maria
JM
Hu
Chiyi
C
Huang
Yueqin
Y
Karam
Elie G
EG
Kawakami
Norito
N
Kovess
Viviane
V
Levinson
Daphna
D
Posada-Villa
Jose
J
Sagar
Rajesh
R
Tomov
Toma
T
Viana
Maria Carmen
MC
Williams
David R
DR
D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000150:complications; D019049:Developed Countries / Q000706:statistics & numerical data; D003906:Developing Countries / Q000706:statistics & numerical data; D039721:Diagnostic and Statistical Manual of Mental Disorders; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000150:complications / Q000453:epidemiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D016015:Logistic Models; D008297:Male; D001523:Mental Disorders / Q000150:complications* / Q000453:epidemiology; D019964:Mood Disorders / Q000150:complications / Q000453:epidemiology; D016017:Odds Ratio; D015995:Prevalence; D013313:Stress Disorders, Post-Traumatic / Q000150:complications / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000150:complications / Q000453:epidemiology; D013405:Suicide / Q000523:psychology* / Q000706:statistics & numerical data; D013406:Suicide, Attempted / Q000523:psychology* / Q000706:statistics & numerical data; D014944:World Health Organization