Descriptions of post-trauma symptoms in combat veterans were published following WWI and WWII, with a recognition of shared symptoms between combat veterans, Holocaust survivors, survivors of railway disasters, and Hiroshima and Nagasaki atomic bomb survivors. Increasing acknowledgement of the chronic psychological problems in many war veterans, especially Vietnam veterans, and of rape survivors convinced clinicians and researchers that significant long-term psychological problems could develop in people with sound personalities when exposed to horrific stressors. In 1980, PTSD became formalized as a distinct diagnosis by the American Psychiatric Association in the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) [12,13,14,15].

PTSD research during the years between publication of the DSM-IV-TR in 2000 and the DSM-5 in 2013 (and revised in 2022) changed the understanding of PTSD and prompted the following revisions in the DSM-5 [1,19]:

In psychodynamic psychiatry, PTSD is the subjective and interpersonal manifestation of disorder that involves meaning. PTSD results from fear over-conditioning, loss of stimulus discrimination and arousal regulation, progressive neural sensitization, over-consolidation of traumatic memory, and malfunction of harm avoidance mechanisms. Effective treatment involves various neuropsychotherapy approaches and eye movement desensitization and reprocessing (EMDR) [20].

Traumatic event: In the DSM-5-TR, a traumatic event is defined as actual or threatened exposure to death, serious injury, or sexual violence. Traumatic events include, but are not limited to, war, torture, sexual or physical assault, natural disasters, accidents, and terrorism. Intentional interpersonal traumatic events such as torture, assault and rape, and prolonged and/or repeated events (e.g., childhood sexual abuse, concentration camp experiences) are more likely than natural events or accidents to result in a traumatic response [1,34].

Complex trauma/PTSD: Complex trauma is a result of exposure to repeated, prolonged, or multiple forms of interpersonal trauma, often under circumstances where escape is not possible due to physical, psychological, maturational, family/environmental, or social constraints [35]. Such traumatic stressors include childhood physical and sexual abuse, coerced conscription as a child soldier, domestic violence, sex trafficking or slave trade, torture, and exposure to genocide campaigns or other forms of organized violence [36].

Rates of PTSD should be viewed in the context of broader population-level exposure rates to traumatic events. Results from a national epidemiologic survey found a lifetime PTSD prevalence of 6% in a sample of more than 36,000 U.S. adults [41]. The sample was surveyed in 2012–2013 and found lifetime PTSD prevalence rates of 4% in men and 8% in women. Also found were past-year prevalence rates of 3% in men and 6% in women. These rates were very similar to those of a large survey from 2001–2003 that found a lifetime PTSD prevalence rate of 6.8% overall, with 3.6% in men and 9.7% in women [41].

Transgenerational trauma was first identified and reported in 1966, based on the clinical observation of offspring of Holocaust survivors [45]. This was quickly followed by many case reports and a growing understanding that "survivor syndrome" was a condition transmitted from one generation to the next. Uncontrolled studies described diverse cognitive and affective symptoms common to survivors and their children, including distrust of the world, impaired parental function, chronic despair, inability to communicate feelings, pervasive fear of danger, separation anxiety, and overprotectiveness within a narcissist family structure. These were followed by the publication of studies identifying resiliency factors [46]. The offspring of Holocaust survivors have been extensively studied to understand the biologic and psychological contributions to intergenerational PTSD, and the relevance of this research extends to survivors and offspring of genocides in Rwanda, Nigeria, Cambodia, Armenia, and the former Yugoslavia [46,47]. The study of intergenerational PTSD transmission has broadened to include survivors and offspring of disasters, impoverished high-crime urban environments, and other environments where trauma exposure is prevalent.

A 2013 systematic review helped clarify the longitudinal course of PTSD [50]. In aggregate, mean PTSD prevalence decreased from 28.8% (range: 3.1% to 87.5%) at 1 month to 17% (range: 0.6% to 43.8%) at 12 months post-trauma. Different trajectories followed exposure to intentional (deliberate infliction of harm) trauma versus non-intentional (all others) trauma. With intentional trauma, median PTSD prevalence at 1, 3, 6, and 12 months was 11.8%, 17.1%, 19.0%, and 23.3%, respectively. Of those who developed PTSD following intentional trauma, 35% remitted within three months, while 39% experienced a chronic course of PTSD. This confirms previous findings that PTSD can spontaneously resolve or persist as a chronic disorder. Following exposure to non-intentional trauma, median PTSD prevalence at 1, 3, 6, and 12 months was 30.1%, 17.8%, 12.9%, and 14.0%, respectively [50].

Long-term trajectories based on retrospective population studies in the United States and Australia found that the greatest symptom decrease occurs during the first 12 months following exposure. A substantial minority continue experiencing PTSD for decades, and a 50% to 60% remission rate occurs between 2 and 10 years post-event [34,51].

PTSD can exact a tremendous toll on sufferers and impair their functioning in many (if not all) areas of life, with consequences that extend beyond the individual to impact family members and society as a whole. PTSD can impose one of the greatest levels of disability possibly experienced with any physical or mental disorder. Persons with PTSD may experience decreased role functioning from work impairment or loss; family discord; and reduced educational attainment, work earnings, marriage attainment, and child rearing. PTSD is associated with an increased risk of suicide, high medical costs, and high social costs. As noted, a high percentage of individuals with PTSD have one or more additional psychiatric disorders, most commonly substance use disorders or major depressive disorder. In Iraq and Afghanistan war veterans, PTSD imposed an estimated cost of between $4 billion and $6 billion over two years from medical care, forgone productivity, and lives lost through suicide [59,60,61,62,63].

Military personnel may confront numerous potentially traumatizing experiences, including military-specific events and those experienced by civilians. Research suggests the most common traumatic events experienced during active duty are witnessing someone badly injured or killed or unexpectedly seeing a dead body. Events most likely to result in the development of PTSD include witnessing atrocities, accidentally injuring or killing another person, and other interpersonal traumas, such as rape, domestic violence, and being stalked, kidnapped, or held captive [6,65].

With innocent civilians used as human shields, children used as "bait" for attacks, calm moments erupting into death and devastation in seconds, and violations of the rules of engagement, the nature of the Iraq and Afghanistan wars impose on the returning veteran an unnatural recalibration of security and sanity. Among returning war veterans, the most common problems involve somatic, emotional, cognitive, behavioral, interpersonal, and psychosocial components. Somatic concerns appear as primary and middle (sleep-maintenance) insomnia, fatigue, headaches, tinnitus, impotence, restlessness, and chronic pain. Emotional and psychological complaints may involve nightmares, racing thoughts (particularly at bedtime), generalized and social anxiety, anger and irritability, impulsive hostility, emotional numbing, hypervigilance, complicated grief, and despair [66].

Historically, the suicide rates in the Army and Marine Corps consistently surpassed general population rates [77]. From 2011 to 2022, the suicide rate for active-duty military increased from 19.8 to 25.1 suicides per 100,000 service members [78]. Although military suicide rates are comparable with rates in the U.S. adult population (after accounting for age and sex), the Department of Defense reports a continued heightened risk, primarily for enlisted male members who are younger than 30 years of age [78]. Factors with the greatest association to suicide risk include depression, relationship strain, financial and vocational loss, and magnitude of life impairment. Clinical presentations with the highest prediction of potential future suicidal behavior are the presence of overwhelming negative thoughts and hopelessness over the future [79].

Most childhood sexual abuse is perpetrated by family members or someone known to the child. Roughly 60% of perpetrators are non-relative acquaintances, such as a family friend, babysitter, or neighbor; 30% are relatives such as fathers, uncles, or cousins; and 10% are strangers [84]. Men are the most common perpetrators with boy or girl victims; women are the perpetrators in 14% of cases against boys and 6% of cases against girls. The Internet is often used to initially contact children by child pornographers and other stranger perpetrators [6].

Common presenting problems in survivors of adult sexual assault include [6]:

Data from a national epidemiologic survey of 34,653 U.S. adults were analyzed to examine PTSD and trauma exposure in gay men, lesbians, and bisexuals. The overall finding was elevated rates of PTSD and exposure to traumatic experiences among persons with minority sexual orientation (Table 1) [89]. A novel finding was that heterosexuals with same-sex partners had rates of PTSD and traumatic experiences similar to gays/lesbians and bisexuals in both genders, suggesting that same-sex exposure, rather than same-sex orientation, was a risk factor [89].

The prevalence of PTSD related to the 2001 attack on the World Trade Center decreased from 9.6% one year after the attack to 4.1% at the four-year follow-up among 455 patients in primary care practices in New York City [108]. However, symptoms may persist for years in up to 40% of adults with PTSD triggered by a terrorist attack [4].

Psychological and behavioral reactions to terrorism are often proportionate to the extent of harmful impact from the attack. Proximity to the attack and the number of attacks are also correlated with symptom severity. Immediate reactions include heightened anxiety, panic attacks, sleep disturbances, substance use problems, absenteeism from work, and retaliatory reactions against minorities groups identified with the terrorists. The initial level of distress often subsides over the first several weeks, although repeated attacks, widespread loss of life, and significant infrastructure damage can elevate and prolong psychological and behavioral reactions. Significant longer-term mental health problems are usually limited to a small proportion of the population and can include traumatic stress symptoms, anxiety disorders, depression, and substance abuse. A common feature among all levels of distress is an ongoing fear of another attack [6].

At-risk professionals include therapists, counselors, social workers, shelter staff, lawyers, healthcare professionals, clergy, journalists, trauma researchers, and psychologists. Individuals are more likely to develop vicarious trauma when caring for trauma survivors in an open, engaged, empathic, dedicated, and responsible style. Immersion into experiences of trauma survivors can alter the identity, worldview, spirituality, professional relationships with clients and colleagues, and personal relationships of the trauma professional [116].

Providers may reduce the risk of vicarious trauma, or minimize the severity of impairment if it develops, through basic self-care activities, including balancing work, play, and rest; adequate diet and exercise; appropriate professional training; communicating with colleagues; ongoing consultation; finding a forum to talk about vicarious trauma experiences; adding support staff; and simply acknowledging the difficulties of the work. Some trauma professionals benefit from identifying problems and contributing factors, specific steps to take, and getting support from friends or colleagues in taking these steps. Restoring meaning and hope is essential because these two provider qualities are undermined by vicarious trauma [116].

While many injury survivors experience PTSD symptoms such as nightmares or intrusive memories in the initial weeks after a physical injury, these symptoms tend to resolve within three months in most patients. However, 10% to 15% will go on to develop chronic PTSD [117]. The extent an injury is life-threatening does not predict the development of PTSD; rates of PTSD for certain soft tissue injuries such as whiplash are similar to severe injury. Patients with severe TBI are less likely to develop PTSD compared to those with mild TBI. Low PTSD rates following severe TBI are likely the result of amnesia and absence of trauma memory [118,119].

Attempting to distinguish between the consequences of physical and psychological torture is difficult, as fear of physical violence is a psychological stressor and psychological torture often leads to physical sequelae, such as pain and sexual dysfunction. Psychological torture intends to humiliate, degrade, or induce an extreme state of fear, as through the use of sham executions or forced viewing of torture. Other common psychological torture methods intend to isolate or disorient a prisoner by blindfolding or sleep deprivation. When physical and psychological torture are combined, the outcome is often severe and chronic psychological morbidity [127]. The primary psychiatric diagnoses in torture survivors are PTSD, depression, anxiety disorders, and chronic pain syndromes, with prevalence rates among treatment-seeking torture survivors of 50% to 67% for PTSD, 33% for depression, 10% for generalized anxiety disorders, and 40% to 70% for chronic pain or somatoform disorders [132,133].

Anger is an emotional state encompassing feelings of variable intensity, ranging from mild annoyance or aggravation to fury and rage. Anger and aggression are related but distinct constructs, and difficulties with anger may not necessarily translate into aggressive behavior. Research has shown that anger is higher among veterans with PTSD relative to those without PTSD, and this relationship between PTSD and anger tends to be stronger in veterans than in civilian populations [134]. When exposed to reminders of their trauma event, these patients show a very strong anger response that differs from the more common anxiety or depressive response in civilians. PTSD is a central and primary risk factor for anger and aggression in military veterans. Clinically, veterans with PTSD often report that anger is the primary problem causing the greatest disruption in their functioning. High levels of anger also interfere with the effectiveness of PTSD treatments [135].

A study of Iraq and Afghanistan war veterans found that more than 50% of individuals with PTSD reported aggressive behavior in the past four months, such as threatening physical violence, property destruction, and fighting [136]. A 2010 survey of 2,797 U.S. veterans returning from deployment in Iraq or Afghanistan found that 40% reported killing or being responsible for killing during deployment. After controlling for combat exposure, killing was a significant predictor of PTSD symptoms, alcohol abuse, anger, and relationship problems [137].

A study of Vietnam veterans found that combat veterans were not significantly angrier than veterans who did not serve in Southeast Asia and that combat veterans with PTSD scored significantly higher than veterans without PTSD on measures of anger, arousal, range of anger-eliciting situations, hostile attitudinal outlook, and tendency to hold anger in. These results suggest that PTSD, rather than warzone duty, is associated with various dimensions of elevated anger [138].

Anger can be a very difficult emotion to deal with and can lead to legal and interpersonal problems, such as divorce or domestic violence. Research has found that anger negatively influences veterans' PTSD treatment outcomes [139]. To improve treatment effectiveness, clinicians should assess veterans' anger, aggression, alcohol use, and fear of anger to elucidate the relationship between these factors [139].

Veterans with PTSD are at much greater risk for perpetrating partner violence than veterans without PTSD. Studies have found that rates of veteran perpetration of intimate partner violence are up to three times higher than among civilians [140,141]. The severity of PTSD symptoms, particularly hyperarousal, is significantly associated with intimate partner violence [142,143]. Most studies have examined rates of aggression among Vietnam veterans several years post-deployment. One study examined partner aggression among male Afghanistan or Iraq veterans who served during Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) and compared it to partner aggression reported by Vietnam veterans with PTSD [144]. Participants were divided into three groups: 27 OEF/OIF veterans with PTSD; 31 OEF/OIF veterans without PTSD; and 28 Vietnam veterans with PTSD. The results suggested that OEF/OIF veterans with PTSD were 1.9 to 3.1 times more likely to perpetrate intimate partner violence than the other two groups [144].

Higher rates of trauma and earlier age of trauma onset are associated with increased violence and victimization in prison [149]. High rates of PTSD and histories of physical and/or sexual abuse have been repeatedly found among incarcerated veterans, inmates in rural prisons and jails, and men in substance abuse treatment. Most studies have suggested a much higher rate of childhood sexual abuse in male inmates than in the general male population [150,151]. Unlike women, men are rarely safer in prison than before incarceration; their risk of sexual assault is increased exponentially, and the constant threat of potentially lethal violence may trigger greater externalizing trauma responses of aggression and violence and high arousal levels that endanger staff and other inmates [152,153].

PTSD is viewed as a maladaptive response to a traumatic stressor, characterized by altered fear-related learning (fear conditioning) and extinction, behavioral sensitization and kindling, and alterations in brain regions and neurotransmitter systems closely linked to these processes. The hypothalamic-pituitary-adrenal (HPA) axis is the primary system activated as a stress response and a potential source of vulnerability to trauma-related psychopathology such as PTSD. Normal response to stress exposure initiates a neuroendocrine cascade in the HPA axis, leading to adrenal gland hypersecretion of the glucocorticoid cortisol. HPA axis activity is tightly controlled through complex regulatory mechanisms of glucocorticoid negative feedback. Glucocorticoids regulate the secretion of hypothalamic corticotropin-releasing factor (CRF) and pituitary adrenocorticotropic hormone. HPA axis activity is also regulated by glucocorticoid receptors (GRs) in the hippocampus and prefrontal cortex [174,175].

Prolonged HPA axis activation from traumatic or chronic stress can induce inappropriate HPA axis adaptation and GR alteration. CRF hypersecretion leads to blunted adrenocorticotropic hormone response to CRF, which suppresses cortisol output. Suppressed cortisol release from dysregulated stress feedback prevents HPA axis self-regulation, which in turn perpetuates a hyperaroused state in stress response pathways. Exposure to single-event traumatic stress upregulates GRs in the hippocampus and prefrontal cortex [174,175,176]. HPA stress response pathways are intimately linked with neurotransmitter systems and key brain regions in PTSD.

Several additional factors involving acute medical/behavioral issues should be considered and assessed in the immediate post-trauma period [70]:

The eight core components of psychological first aid are [183]:

The long-standing observation that at least 75% of persons exposed to a traumatic event do not develop PTSD, along with the understanding that traumatic event memory is not permanently stored shortly after trauma exposure, has prompted the hypothesis that correctly timed intervention may disrupt trauma memory storage and prevent the development of PTSD. As such, some experts believe that intervention timed for delivery shortly after exposure to a traumatizing event may prevent the development of PTSD. Memory consolidation refers to the transition of trauma event memory from an unstable labile state into a stable state, at which point it becomes stored as long-term memory. Secondary prevention intends to disrupt the process of trauma memory consolidation in the immediate post-trauma period. The "golden hours" of opportunity for intervention to disrupt memory consolidation is thought to range from moments after the event up to 72 hours post-exposure [172,184]. Selection of approaches for secondary prevention have been informed by the findings that a repressive coping style, whereby the patient utilizes a cognitive and emotional strategy of ignoring and diverting attention from threatening or disturbing memory, offers substantial protection from the development of PTSD [184,185].

Research has identified interventions that interfere with the spontaneous recovery process by promoting consolidation and increasing the risk of PTSD [184]. These include psychological debriefing and benzodiazepines.

Persistence of significant distress and/or diminished social or occupational functioning longer than 2 days but less than 30 days post-trauma suggests the presence of ASD. ASD and PTSD share substantial symptom overlap, and the primary distinction is time frame, as PTSD diagnosis requires symptom presence 30 days or longer post-trauma.

Brief cognitive-behavioral therapy (bCBT) is the best-validated early intervention for reducing current post-trauma distress symptoms, preventing PTSD, and reducing PTSD severity if it develops [70,199]. It should only be given to symptomatic patients, especially to those meeting ASD criteria. Delivered in four to five sessions, bCBT combines education, breathing training and relaxation, imaginal and in vivo exposure, and cognitive restructuring. bCBT has been shown to equally benefit survivors of sexual and nonsexual assault and is suggested for initiation not earlier than 14 days post-trauma [70,199].

The CAPS-5 is a 30-item structured interview considered the gold standard in PTSD assessment. It may be used for current past-month PTSD diagnosis, lifetime diagnosis of PTSD, and assessment of past-week PTSD symptoms [204]. The CAPS-5 assesses for all 20 DSM-5-TR PTSD symptoms and obtains information related to the onset and duration of symptoms, subjective distress, symptom impact on social and occupational functioning, symptom improvement from previous CAPS-5 administration, overall response validity, overall PTSD severity, and dissociative subtypes of depersonalization and derealization [204].

Research involving veterans has explored possible racial/cultural differences in PTSD risk or presentation. While higher PTSD rates have been found in individuals who are Black or Hispanic, this is primarily attributable to greater exposure to traumatic stressors. Otherwise, few to no racial or ethnic differences have been found in PTSD prevalence. Researchers have conducted studies of PTSD in ethnic minority Vietnam veteran populations, and while the results are not consistent, the overall finding is that most ethnic minority Veteran groups have a higher rate of PTSD than White veterans [206]. Differences in samples, measures, and whether the interviewer and participant were racially paired affected the results. Ethnic minority veterans were more likely to disclose problems or to engage in treatment when paired with a clinician of the same race [207]. Clinical manifestation and treatment response in combat-related PTSD has also been found to be similar among various races; however, present findings highlight a lack of research focused on understanding cultural factors related to the assessment and treatment of PTSD [70,208,209].

In addition, seeking behavioral health care has long been stigmatized by military "warrior" culture. Veterans are likely to minimize their impairment and distress as the result of stoic expectations of them when engaging in psychological trauma-prone activities; training that prepares them for dangerous situations; stoicism and a machismo response instilled by military culture and indoctrination; fear of their diagnosis or avoidance in discussing their war experiences; and fear of negative impact on their military career options. Combat medics are exposed to graphic and horrifying battlefield injuries and deaths and may avoid seeking help because the reliance on them by many others for medical support and psychological, spiritual, and emotional guidance creates the belief of needing to be self-sufficient [66].

Prolonged exposure is often included as a component with other approaches, termed CBT-mixed therapy. Elements of CBT-mixed therapy may include psychoeducation, self-monitoring, stress management, relaxation training, skills training, exposure (imaginal, in vivo, or both), cognitive restructuring, guided imagery, mindfulness training, breathing retraining, crisis/safety planning, and relapse prevention [266].

This therapy consists of exposure within one session (within-session habituation) or across a series of sessions (between-session habituation) and involves three components:

The first step of treatment is to establish conditions and an atmosphere of safety to the fullest extent possible. The patient cannot respond to or make progress with therapy if a relative degree of safety is not available or attainable [33,36].

SSRIs are widely recommended as first-line agents in the treatment of PTSD, with demonstrated efficacy in reducing the global, re-experiencing, avoidance/numbing, and hyperarousal symptoms of PTSD [70,199]. SSRI maintenance therapy has shown a substantial and consistent effect in PTSD by preventing relapse and has demonstrated value in long-term PTSD management. Comparison studies have found efficacy of improving PTSD symptoms with fluoxetine, paroxetine, and sertraline, with clear evidence of patients achieving remission at 12 weeks with paroxetine and insufficient evidence of 12-week remission with fluoxetine and sertraline [70,266,294,295]. Pharmacologic studies generally did not report loss of PTSD diagnosis as an outcome, and studies mostly did not report evidence for other outcomes of interest, such as anxiety symptoms, quality of life, disability or functional impairment, and return to work or active duty [266].

If pharmacotherapy is necessary, SSRIs or SNRIs may be considered. For patients who are not responding to SSRIs/SNRIs and nonpharmacologic interventions, low-dose anti-adrenergics or low-dose atypical antipsychotics, such as risperidone or quetiapine, may be initiated. If the patient is still not improving or is worsening, referral to specialty care is indicated.