Suicide is the 11th leading cause of death in the United States; it accounts for more than 34,000 deaths per year.1 And an even greater number of people attempt suicide. Based on data from community surveys, approximately 5% of adults have made a serious suicide attempt.2
Mental health problems are some of the best-known and well-studied risk factors linked to suicidal ideation, suicide attempts, and suicide mortality. Approximately 90% of all individuals who completed suicide met criteria for 1 or more diagnosable psychiatric conditions. Mental health conditions most strongly associated with fatal and nonfatal suicide attempts include depression, bipolar disorder, schizophrenia, posttraumatic stress disorder, and alcohol and/or drug use disorders.2-4 Because mental health treatment providers are in regular contact with patients at risk for suicide, they are an important resource for early detection and prevention of suicidal behavior.
Substance use and suicide risk
Although it is difficult to compare the relative impact among different mental health problems with the risk of suicide, alcohol and drug use disorders have been found to be strongly related to suicide risk.3,5 Individuals with a substance use disorder (ie, either a diagnosis of abuse or dependence on alcohol or drugs) are almost 6 times more likely to report a lifetime suicide attempt than those without a substance use disorder.2 Numerous studies of individuals in drug and alcohol treatment show that past suicide attempts and current suicidal thoughts are common.6-8 Recent evidence from veterans indicates that men with a substance use disorder are approximately 2.3 times more likely to die by suicide than those who are not substance abusers. Among women, a substance use disorder increases the risk of suicide 6.5-fold.9
Identifying substance abusers at greatest risk for suicide
Although a consistent association exists between substance use disorders and suicidal behaviors, the vast majority of those with substance-related problems will never die by suicide. Therefore, it is important to identify those individuals with substance use disorders who might be at particularly high risk for suicide.
Many risk factors for suicide in the general population also apply to those with substance use disorders. Older men with substance use disorders are at greater risk for nonfatal attempts and for death by suicide than are younger persons.10,11 Past suicide attempts are a strong risk factor for subsequent suicidal behaviors in those with substance use disorders.12 Depressed mood is a risk factor for suicidal behaviors in the general population and also predicts a greater likelihood of suicide in those with alcohol or drug use disorders.3,6,10 The link between depression and suicidal behaviors in those with substance use disorders may be particularly strong given the high comorbidity between mood and substance use disorders.13 Although it has not been examined thoroughly, independent mood disorders and substance-induced mood disorders are likely to confer risk for suicide.
Emerging research suggests that some individuals with particular types of substance use and abuse may be more likely to engage in suicidal behaviors. For example, individuals who use opiates, cocaine, and sedatives may have a noticeably higher risk of suicide than those who use other drugs.12,14-16 Among those with an alcohol use disorder, a greater severity of recent drinking is associated with the greater likelihood of suicide attempt and suicide mortality.17,18 Co-occurring alcohol and drug use disorders may be particularly strong indicators of increased risk of suicide.19 Thus, the severity of substance use disorders (ie, a greater number of substances or misuse of more than 1 substance) may predict a greater likelihood of suicide.
Violent behavior toward others
The tendency to engage in violent behavior is a potentially important risk factor for suicide in substance abusers. Up to 75% of those who begin addiction treatment report having engaged in violent behavior (eg, physical assault, mugging, attacking others with a weapon).20,21 Emerging research also indicates that violence may partially account for the connection between substance abuse and suicide risk. For example, in those seeking treatment for substance use disorders, the perception that they have difficulty in controlling their own violent behavior was associated with a greater likelihood of a prior suicide attempt.22 Tiet and colleagues22 hypothesized that individuals who have difficulty in controlling their anger may be more likely to act impulsively, thus turning the violence on themselves rather than on others.
Individuals with alcohol use disorders and prior aggressive behavior are more likely to report suicidal thoughts or past suicide attempts.6,23 In one recent study of more than 6000 adults who began addictions treatment, those who had committed serious violent acts (eg, rape, murder, assault resulting in serious injury) were more than twice as likely to report multiple suicide attempts. This finding held true even after statistically controlling for demographic characteristics, depression, and past victimization.6
Another study compared accident victims with individuals who completed suicide. Violent behavior in an individual’s last year of life was linked to a higher likelihood of suicide, even when controlling for alcohol use disorders and other potential suicide risk factors.24
A growing body of literature has identified the link between substance use disorders, interpersonal violence, and risk of suicide.
This article reviews this literature and provides suggestions for how to identify substance use disorder patients who may be at elevated risk for suicide.
Mental health providers should be aware that individuals with substance use disorders are at elevated risk for suicide and should include questions about prior violence toward others as part of a comprehensive suicide risk assessment.
1. Centers for Disease Control and Prevention. National Center for Injury Prevention & Control: Data & Statistics (WISQARSTM); 2009. http://www.cdc.gov/injury. Accessed November 16, 2010.
2. Kessler RC, Borges G, Walters EE. Prevalence of and risk factors for lifetime suicide attempts in the National Comorbidity Survey. Arch Gen Psychiatry. 1999;56:617-626.
3. Harris EC, Barraclough B. Suicide as an outcome for mental disorders. A meta-analysis. Br J Psychiatry. 1997;170:205-228.
4. Cavanagh JT, Carson AJ, Sharpe M, Lawrie SM. Psychological autopsy studies of suicide: a systematic review [published correction appears in Psychol Med. 2003;33:947]. Psychol Med. 2003;33:395-405.
5. Wilcox HC, Conner KR, Caine ED. Association of alcohol and drug use disorders and completed suicide: an empirical review of cohort studies. Drug Alcohol Depend. 2004;76(suppl):S11-S19.
6. Ilgen MA, Burnette ML, Conner KR, et al. The association between violence and lifetime suicidal thoughts and behaviors in individuals treated for substance use disorders. Addict Behav. 2010;35:111-115.
7. Roy A. Characteristics of cocaine-dependent patients who attempt suicide. Am J Psychiatry. 2001;158:1215-1219.
8. Roy A. Characteristics of cocaine dependent patients who attempt suicide. Arch Suicide Res. 2009;13:46-51.
9. Ilgen MA, Bohnert AS, Ignacio RV, et al. Psychiatric diagnoses and risk of suicide in veterans. Arch Gen Psychiatry. 2010;67:1152-1158.
10. Conner KR, Beautrais AL, Conwell Y. Risk factors for suicide and medically serious suicide attempts among alcoholics: analyses of Canterbury Suicide Project data. J Stud Alcohol. 2003;64:551-554.
11. Darke S, Ross J. Suicide among heroin users: rates, risk factors and methods. Addiction. 2002;97:1383-1394.
12. Ilgen MA, Harris AH, Moos RH, Tiet QQ. Predictors of a suicide attempt one year after entry into substance use disorder treatment. Alcohol Clin Exp Res. 2007;31:635-642.
13. Conner KR, Pinquart M, Gamble SA. Meta-analysis of depression and substance use among individuals with alcohol use disorders. J Subst Abuse Treat. 2009;37:127-137.
14. Maloney E, Degenhardt L, Darke S, et al. Suicidal behaviour and associated risk factors among opioid-dependent individuals: a case-control study. Addiction. 2007;102:1933-1941.
15. Darke S, Ross J, Lynskey M, Teesson M. Attempted suicide among entrants to three treatment modalities for heroin dependence in the Australian Treatment Outcome Study (ATOS): prevalence and risk factors [published correction appears in Drug Alcohol Depend. 2004;73:315]. Drug Alcohol Depend. 2004;73:1-10.
16. Wines JD Jr, Saitz R, Horton NJ, et al. Suicidal behavior, drug use and depressive symptoms after detoxification: a 2-year prospective study. Drug Alcohol Depend. 2004;76(suppl):S21-S29.
17. Cornelius JR, Salloum IM, Day NL, et al. Patterns of suicidality and alcohol use in alcoholics with major depression. Alcohol Clin Exp Res. 1996;20:1451-1455.
18. Murphy GE, Wetzel RD, Robins E, McEvoy L. Multiple risk factors predict suicide in alcoholism. Arch Gen Psychiatry. 1992;49:459-463.
19. Preuss UW, Schuckit MA, Smith TL, et al. Comparison of 3190 alcohol-dependent individuals with and without suicide attempts. Alcohol Clin Exp Res. 2002;26:471-477.
20. Burnette ML, Ilgen M, Frayne SM, et al. Violence perpetration and childhood abuse among men and women in substance abuse treatment. J Subst Abuse Treat. 2008;35:217-222.
21. Chermack ST, Murray RL, Walton MA, et al. Partner aggression among men and women in substance use disorder treatment: correlates of psychological and physical aggression and injury. Drug Alcohol Depend. 2008;98:35-44.
22. Tiet QQ, Ilgen MA, Byrnes HF, Moos RH. Suicide attempts among substance use disorder patients: an initial step toward a decision tree for suicide management. Alcohol Clin Exp Res. 2006;30:998-1005.
23. Koller G, Preuss UW, Bottlender M, et al. Impulsivity and aggression as predictors of suicide attempts in alcoholics. Eur Arch Psychiatry Clin Neurosci. 2002;252:155-160.
24. Conner KR, Cox C, Duberstein PR, et al. Violence, alcohol, and completed suicide: a case-control study. Am J Psychiatry. 2001;158:1701-1705.
25. Ilgen MA, Chermack ST, Murray R, et al. The association between partner and non-partner aggression and suicidal ideation in patients seeking substance use disorder treatment. Addict Behav. 2009;34:180-186.
26. Conner KR, Duberstein PR, Conwell Y. Domestic violence, separation, and suicide in young men with early onset alcoholism: reanalyses of Murphy’s data. Suicide Life Threat Behav. 2000;30:354-359.
27. Chermack ST, Fuller BE, Blow FC. Predictors of expressed partner and non-partner violence among patients in substance abuse treatment. Drug Alcohol Depend. 2000;58:43-54.
28. Conner KR, Ilgen MA. Substance use and suicidal behaviour. In: O’Connor R, Platt S, Gordon J, eds. International Handbook of Suicide Prevention. Chichester, UK: Wiley-Blackwell. In press.
29. Conner KR, Swogger MT, Houston RJ. A test of the reactive aggression-suicidal behavior hypothesis: is there a case for proactive aggression? J Abnorm Psychol. 2009;118:235-240.
30. Wojnar M, Ilgen MA, Czyz E, et al. Impulsive and non-impulsive suicide attempts in patients treated for alcohol dependence. J Affect Disord. 2009;115:131-139.
31. Joiner TE. Why People Die by Suicide. Cambridge, MA: Harvard University Press; 2005.
32. Brown GK, Ten Have T, Henriques GR, et al. Cognitive therapy for the prevention of suicide attempts: a randomized controlled trial. JAMA. 2005;294:563-570.