Suicide in war veterans: the role of comorbidity of PTSD and depression

Many wars have been fought during the history of civilization. Approximately 30 armed conflicts are currently occurring around the globe, involving more than 25 countries. There are millions of war veterans around the world, many of whom are suffering from the psychological and/or physical wounds of war.

The psychological toll of war is very heavy. It has recently been reported that a US Army Sergeant shot and killed five fellow servicemen at a military counseling center in Baghdad on 11 May 2009 [101]. Concerned about his mental state, his superiors had referred him to a stress clinic where he killed five people including two doctors. It was the deadliest incidence of soldier-on-soldier violence in the 6-year Iraq war.

Suicidal behavior is a major problem among war veterans [1–5]. It has been estimated that from time of discharge until the early 1980s, between 8000 and 9000 Vietnam veterans died by suicide [2]. In 2002, British veterans of the 3-month Falklands conflict (1982) claimed that more Falklands veterans had died by suicide (n = 264) since the conflict ended than died during the conflict itself (n = 256) [3]. Suicides among active-duty soldiers in the US Army reached a 28-year high in 2008, continuing a 4-year trend that has persisted despite ongoing military efforts to curb such deaths [4]. Approximately two-thirds of the 446 soldiers who have committed suicide since 2005 have done so during deployment or after returning from deployment to Iraq or Afghanistan [4]. In addition to experiencing elevated rates of suicide, nonfatal suicide attempts and suicidal ideation occur at high rates among veterans. Among a large national sample of patients seeking substance abuse treatment at the US Veterans’ Administration Hospitals, 4% reported a nonfatal suicide attempt in the past month [5]. Studies have consistently demonstrated that there is an increased risk of accidental death in military populations exposed to war and trauma. Many of the accidental deaths occurring in war veterans may actually be suicidal deaths.

Many war veterans suffer from post-traumatic stress disorder (PTSD), depression or both disorders [6]. The majority of US soldiers in Iraq were exposed to some kind of traumatic, combat-related situations, such as being attacked or ambushed (92%), seeing dead bodies (94.5%), being shot at (95%) and/or knowing someone who was seriously injured or killed (86.5%) [7]. Repeated deployments are difficult for many service members. In 2006, a US government team collected data from surveys and qualitative interviews from more than 1300 soldiers and nearly 450 marines [8]. Soldiers deployed several times to Iraq were more likely to fulfill criteria for acute stress, PTSD, depression or any mental disorder than those who were deployed once. Soldiers deployed several times were 1.6-times more likely to screen positive for PTSD than those who were deployed once and were 1.7-times more likely to have depression. Importantly, no specific cut-off for duration of deployment eliminated the risk.

Suicidal behavior among war veterans may frequently be related to depression and/or PTSD. The risk of suicide attempts among the PTSD population is six-times greater than in the general population [9] and even higher among treatment-seeking war veterans with PTSD [10]. In one study, veterans were assessed for suicidal thinking and behavior, as well as symptoms of PTSD and depression [11]. Thoughts of ending one’s life and a previous suicide attempt were significantly correlated with a diagnosis of PTSD. Veterans with a diagnosis of PTSD and major depressive disorder (MDD) or dysthymia were also more likely to report suicidal thinking and behaviors than veterans with only one of the diagnoses.

The percentage of veterans who die from combat-related injuries is decreasing over time (22% in World War II to 16% in Vietnam to 8.8% in the recent wars in Iraq and Afghanistan), suggesting that there is now a larger proportion of veterans living with the effects of their injuries [12]. Veterans who have activity limitations are more likely to die by suicide than veterans who do not have such limitations.

I have previously proposed that some, or all, individuals diagnosed with comorbid PTSD and MDD have a separate psychobiological condition that can be termed ‘post-traumatic mood disorder’ (PTMD) [13]. This idea was based on the fact that a significant number of studies suggested that patients suffering from comorbid PTSD and MDD differed clinically and biologically from individuals with PTSD or MDD alone. Individuals with comorbid PTSD and MDD are characterized by having greater severity of symptoms, increased suicidality and a higher level of impairment in social and occupational functioning compared with individuals with PTSD or MDD alone. Neurobiological evidence supporting the concept of PTMD includes the findings from neuroendocrine challenge, cerebrospinal fluid, neuroimaging, sleep and other studies.

I have recently proposed a model of suicidal behavior in war veterans with PTMD [1]. The model consists of the following components:

• • Genetic factors: converging evidence from multiple studies supports a role for genetic influences in the etiology of PTSD, depression and suicidal behavior;

• • Prenatal development: antenatal factors may affect the psychological development of offspring;

• • Biological and psychosocial influences from birth to mobilization/deployment: various biological and psychological factors may affect the sensitivity of a person to traumatic events and play a role in the development of PTSD, depression and suicidal behavior;

• • Mobilization/predeployment stress;

• • Combat stress, traumatic brain injury and physical injury;

• • Postdeployment stress, including interpersonal, family and occupational difficulties;

• • Biological and psychosocial influences after deployment, such as perceived social support, stressful situations, ongoing threat to safety, state of health, nutrition and alcohol and drug use;

• • Triggers (precipitants) of a suicidal acts including interpersonal losses or conflicts, and financial and job problems;

• • Suicidal act.

The first four components determine vulnerability to combat stress. The first seven components determine predisposition to suicidal behavior, a key element that differentiates PTMD patients who are at high risk from those at lower risk. Suicidal behavior in PTMD can be attributed to the coincidence of a trigger with a predisposition for suicidal behavior.

The best approach to preventing suicide is usually a proactive one. Suicide prevention in war veterans with psychiatric disorders should focus on:

• • Improvement in recognition of psychiatric problems;

• • Treating PTSD, depression, alcohol and drug abuse and other psychiatric conditions;

• • Preventing a relapse when the patient is in remission;

• • Treating suicidal ideation;

• • Treating medical and neurological disorders, including traumatic brain injury;

• • Social support;

• • Suicide prevention hotlines;

• • Reducing stigma for mental illness in the military;

• • Reducing access to firearms.

Sufferers of PTSD and MDD are the casualties of wars you do not often hear about – the soldiers who die of self-inflicted wounds. We should prevent these casualties.

Financial & competing interests disclosure

The author has no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.