Elsevier

Comprehensive Psychiatry

Volume 53, Issue 7, October 2012, Pages 915-930
Comprehensive Psychiatry

A meta-analysis of the association between posttraumatic stress disorder and suicidality: the role of comorbid depression

https://doi.org/10.1016/j.comppsych.2012.02.009Get rights and content

Abstract

Objective

A considerable number of studies have reported an increased frequency of suicidal behaviors among individuals diagnosed with posttraumatic stress disorder (PTSD). This study aims, first, to provide a comprehensive systematic review and meta-analysis of the association between a PTSD diagnosis and frequency of suicidality and, second, to examine the role of comorbid depression in the association between suicidality and PTSD.

Methods

Searches of Medline (June 2010), EMBASE (June 2010), PsycINFO (June 2010), PILOTS (June 2010), and Web of Science (June 2010) were conducted to identify studies that examined the association between PTSD and suicidality. The studies had to include an effect size of the association between PTSD and suicidality to be included in the meta-analysis. Sixty-three studies were eligible for inclusion in the meta-analysis. Overall and subgroup effect sizes were examined.

Results

A highly significant positive association between a PTSD diagnosis and suicidality was found. The PTSD-suicidality association persisted across studies using different measures of suicidality, current and lifetime PTSD, psychiatric and nonpsychiatric samples, and PTSD populations exposed to different types of traumas. Comorbid major depression significantly compounded the risk for suicide in PTSD populations.

Conclusion

The current meta-analysis provides strong evidence that a PTSD diagnosis is associated with increased suicidality. The crucial role of comorbid major depression in the etiology of suicidality in PTSD is also supported.

Introduction

Increased frequency of suicidal behaviors (suicidal thoughts, suicidal plans, or suicidal acts) has been reported in posttraumatic stress disorder (PTSD) [1], [2], [3], [4]. Similar to other common Axis I psychiatric disorders, such as major depression, substance use disorders, and psychoses, PTSD is strongly associated with increased frequency of suicidality [5], [6], [7], [8], [9], [10]. Comorbid psychiatric disorders and especially comorbid major depression have been found to substantially increase the levels of suicidality in those with PTSD [4], [11], [12], [13]. There is also some evidence that comorbid major depression mediates the relationship between suicidal ideation and PTSD [14]. One comprehensive narrative review has been published in the area of PTSD and suicidality, which aimed to summarize the available research findings on the relationship between suicidality and PTSD. Most of the studies indicated a strong positive association between PTSD and suicidality. The association between suicidality and PTSD appeared to hold across different populations, such as war veterans, victims of interpersonal victimization in childhood and/or in adulthood, PTSD samples with mixed traumas, psychiatric populations, and nonpsychiatric community samples. A considerable proportion of the studies also indicated that apart from PTSD, a diagnosis of major depression significantly increased suicidal risk. Moreover, the presence of PTSD and major depression comorbidity was associated with substantially increased suicidal risk compared with a PTSD diagnosis alone [15]. One important limitation of the above narrative review is that it was largely descriptive.

Meta-analytic procedures offer the best means of summarizing and statistically estimating the overall significance of findings derived from individual studies. One existing systematic review in the area of PTSD and suicidality indicated that a diagnosis of PTSD is positively associated with increased suicide attempts, and suicidal ideation, but not completed suicides. These findings were based on extracting and computing φ coefficients from 25 independent studies. This is a limited number of studies considering that more than 60 published studies have reported an association between PTSD and suicidality. In addition, no subgroup analyses were conducted to examine further the association of PTSD and suicidality. Finally, the authors concluded that the association between PTSD and suicidality remained after controlling for comorbid disorders including depression but also reported evidence that depression mediates the relationship between PTSD and suicidality [16]. Both of these contradictory outcomes concerning the role of depression in the association between suicidality and PTSD were based on a narrative interpretation of the extant literature and not by applying meta-analytic procedures.

Therefore, we conducted a comprehensive meta-analysis that aimed to expand and update the findings in the literature concerning the association between suicidality and PTSD. The term suicidality in this meta-analysis comprised a range of suicidal tendencies including suicidal thoughts, behaviors, plans, attempts, and successful suicides. The broad definition of suicidality used in this meta-analysis is justified by the following 2 reasons. First, the aim of this meta-analysis was to adopt an inclusive approach to provide a comprehensive quantitative account of the extant literature findings on PTSD and suicidality. After the results of the initial analysis of the link between suicidality and PTSD, a series of subsequent analyses (eg, subgroup analyses and meta-regression analyses) were planned to examine potential sources of heterogeneity among the studies included in the meta-analysis. Second, 2 previous reviews (1 narrative review and 1 systematic but less comprehensive review) in the area of PTSD and suicidality have been conducted, both of which used an equivalent definition of the term suicidality [15], [16]. The adoption of the same methodology with previous reviews in defining suicidality facilitates the direct comparison of the current findings with the results of these 2 reviews. The specific objectives of this meta-analysis were to (1) systematically quantify the research findings on the association of PTSD and suicidality across a large number of studies, (2) examine the association of suicidality and PTSD across different PTSD populations (ie, index trauma, psychiatric vs community samples) and across studies using different measures of PTSD (current vs lifetime, interviews vs questionnaires), and (3) examine the role of comorbid depression in the association between PTSD and suicidality by applying meta-regression procedures. Based on the existing literature, it was predicted that PTSD would be significantly positively associated with increased levels of suicide attempts and suicidal ideation. It was also predicted that the association between suicidality and PTSD would pertain across psychiatric and nonpsychiatric samples and across different trauma populations. Finally, it was hypothesized that the presence of comorbid depression would increase suicide risk in those with PTSD.

Section snippets

Inclusion and exclusion criteria

Studies were included in the meta-analysis if they met the following criteria:

  • (a)

    They were published in a peer-reviewed journal in the English language.

  • (b)

    They reported original research findings regarding the relationship between PTSD and suicidality.

  • (c)

    The sample comprised participants 15 years or older.

  • (d)

    They included any measure of PTSD and any measure of suicidality (suicidal ideation, plans, behaviors, attempts, and successful suicides).

  • (e)

    They contained outcome measures that reflected the association

Results

The search strategy yielded 246 results. Of these, 165 studies were empirical English-language studies. Of the 165 studies, 85 were identified as meeting the initial inclusion criteria. However, of the 85 studies, 19 did not provide an outcome measure of the association between PTSD and suicidality, and thus, they were excluded from further analysis. Two studies [1], [20] were excluded because they reported the same data in more recent articles [21], [22]. Finally, 5 studies assessed the

Discussion

The aim of the current meta-analysis was 2-fold: first, to examine the association between PTSD and suicidality and, second, to investigate the impact of depression on the association between PTSD and suicidality. Overall, the findings fully supported our initial hypothesis that a PTSD diagnosis would be associated with heightened rates of suicidality. In addition, consistent with our prediction, higher levels of comorbid depression in the PTSD groups compared with controls were associated with

Conclusions and implications

Taken as a whole, this pattern of findings confirms that PTSD, either as a primary or secondary diagnosis, is significantly associated with an increased risk for suicide. In addition, the findings of this meta-analysis further contribute to the existing literature, which indicates that individuals having psychiatric disorders are at increased risk for suicide [5]. Similarly to PTSD, a considerable number of other psychiatric diagnoses have been identified in the literature to compound risk for

References (101)

  • J.L. Strauss et al.

    Comorbid posttraumatic stress disorder is associated with suicidality in male veterans with schizophrenia or schizoaffective disorders

    Schizophr Res

    (2006)
  • R.E. Villagomez et al.

    Post-traumatic stress disorder among inner city methadone maintenance patients

    J Subst Abuse Treat

    (1995)
  • S. Darke et al.

    Attempted suicide among entrants to three treatment modalities for heroin dependence in the Australian Treatment Outcome Study (ATOS): Prevalence and risk factors

    Drug Alcohol Depend

    (2004)
  • Y. Ben-Ya' acov et al.

    Posttraumatic symptoms and suicide risk

    Pers Individ Dif

    (2004)
  • Y.W. Chen et al.

    Lifetime rates of suicide attempts among subjects with bipolar and unipolar disorders relative to subjects with other Axis I disorders

    Biol Psychiatry

    (1996)
  • C. Bolton et al.

    Developing psychological perspectives of suicidal behavior and risk in people with a diagnosis of schizophrenia: we know they kill themselves but do we understand why?

    Clin Psychol Rev

    (2007)
  • L. Claes et al.

    Comparison of non-suicidal self-injurious behavior and suicide attempts in patients admitted to a psychiatric crisis unit

    Pers Individ Diff

    (2010)
  • M. Amir et al.

    Suicide risk and coping styles in posttraumatic stress disorder patients

    Psychother Psychosom

    (1999)
  • S. Nad et al.

    Spiritual well-being, intrinsic religiosity, and suicidal behavior in predominantly catholic Kroatian Vietnam veterans with chronic posttraumatic stress disorder. A case control study

    J Nerv Ment Dis

    (2008)
  • M.A. Oquendo et al.

    Association of comorbid posttraumatic stress disorder and major depression with greater risk for suicidal behavior

    Am J Psychiatry

    (2003)
  • N. Tarrier et al.

    Suicide risk in civilian PTSD patients. Predictors of suicide ideation, planning and attempts

    Soc Psychiatry Psychiatr Epidemiol

    (2004)
  • J.R. Cougle et al.

    Anxiety disorders and suicidality in the National Comorbidity Survey-Replication

    J Psychiatr Res

    (2008)
  • J.R. Davidson et al.

    Post-traumatic stress disorder in the community: an epidemiological study

    Psychol Med

    (1991)
  • J. Sareen et al.

    Physical and mental comorbidity, disability, and suicidal behavior associated with posttraumatic stress disorder in a large community sample

    Psychosom Med

    (2007)
  • J. Sareen et al.

    Anxiety disorders associated with suicidal ideation and suicide attempts in the national comorbidity survey

    J Nerv Ment Dis

    (2005)
  • H.C. Wilcox et al.

    Posttraumatic stress disorder and suicide attempts in a community sample of urban American young adults

    Arch Gen Psychiatry

    (2009)
  • T.A. Bullman et al.

    Posttraumatic stress disorder and the risk of traumatic deaths among Vietnam veterans

    J Nerv Ment Dis

    (1994)
  • K. Clover et al.

    Posttraumatic stress disorder among deliberate self-poisoning patients

    J Trauma Stress

    (2004)
  • T.W. Freeman et al.

    Dissociative symptoms in posttraumatic stress disorder subjects with a history of suicide attempts

    J Nerv Ment Dis

    (1995)
  • A.S. Leiner et al.

    Intimate partner violence, psychological distress, and suicidality: a path model using data from African American women seeking care in an urban emergency department

    J Fam Violence

    (2008)
  • K. Krynsinska et al.

    Post-traumatic stress disorder and suicide risk: a systematic review

    Arch Suicide Res

    (2010)
  • Borenstein M. www.Meta-analysis.com,...
  • L.V. Hedges et al.

    Statistical methods for meta-analysis

    (1985)
  • M. Borenstein et al.

    Comprehensive meta-analysis (Version 2.2.034) [Computer software]

    (2005)
  • D.G. Campbell et al.

    Prevalence of depression-PTSD comorbidity: implications for clinical practice guidelines and primary care-based interventions

    J Gen Intern Med

    (2007)
  • D. Chan et al.

    Health care utilization and it costs for depressed veterans with and without comorbid PTSD symptoms

    Psychiatr Serv

    (2009)
  • M. Kotler et al.

    Anger, impulsivity, social support and suicide risk in patients with posttraumatic stress disorder

    J Nerv Ment Dis

    (2001)
  • M.K. Nock et al.

    Cross-national analysis of the associations among mental health disorders and suicidal behavior: findings from the WHO mental health surveys

    PLoS Med

    (2009)
  • P.N. Pfeiffer et al.

    Comorbid anxiety as a suicide risk factor among depressed veterans

    Depress Anxiety

    (2009)
  • J.R. Cougle et al.

    PTSD, depression and their comorbidity in relation to suicidality: cross-sectional and prospective analyses of a national probability sample of women

    Depress Anxiety

    (2009)
  • E. Maloney et al.

    Suicidal behaviour and associated risk factors among opioid-dependent individuals: a case-control study

    Addiction

    (2007)
  • T. Caldera et al.

    Psychological impact of the hurricane Mitch in Nicaragua in a one-year perspective

    Soc Psychiatry Psychiatr Epidemiol

    (2001)
  • G.A. Clum et al.

    Diagnostic morbidity and its relationship to severity of ideation for a nonpsychiatric sample of chronic and severe suicide ideators

    J Psychopathol Behav Assess

    (1997)
  • R.A. Desai et al.

    Mental health service delivery and suicide risk: the role of individual patient and family factors

    Am J Psychiatry

    (2005)
  • M.A. Eggleston et al.

    Suicidality, aggression and other treatment considerations among pregnant, substance-dependent women with posttraumatic stress disorder

    Compr Psychiatry

    (2009)
  • M. Ferrada-Noli et al.

    Suicidal behavior after severe trauma. Part 1: PTSD diagnoses, psychiatric comorbidity, and assessments of suicidal behavior

    J Trauma Stress

    (1998)
  • S.K. Floen et al.

    Psychiatric diagnoses, trauma, and suicidiality

    Ann Gen Psychiatry

    (2007)
  • S.R. Fordwood et al.

    Suicide attempts among depressed adolescents in primary care

    J Clin Child Adolesc Psychol

    (2007)
  • Q. Fu et al.

    A twin study of genetic and environmental influences on suicidality in men

    Psychol Med

    (2002)
  • R.M. Giaconia et al.

    Comorbidity of substance use and post-traumatic stress disorders in a community sample of adolescents

    Am J Orthopsychiatry

    (2000)
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