Post traumatic stress disorder (PTSD) is a severe disorder consisting of a widespread range of symptoms following a traumatic event which exceeds the person's coping skills. Some occupational groups (like fire-fighters, police officers, health and social workers, bank employees and journalists) are more prone to the development of PTSD due to the unique demands of their jobs and an increased likelihood of being exposed to trauma. This article provides an overview of the main symptoms, prevalence rates, risk factors and treatment of PTSD, as well as a discussion of the strategies of prevention and rehabilitation with a concentrated focus on occupational settings.
PTSD is an emotional and physical change that develops after exposure to a psychologically traumatic event, which is beyond ones usual experiences and has to be taken seriously as a disease of clinical significance . PTSD is one of the most severe psychological disorders and has a strong impact on the life of the affected person because it exceeds one’s possibilities of coping. It endures longer and is less frequent than an acute stress response and may also occur belatedly after months or years. Such events may be overwhelming also for emergencies forces workers and other employees of special occupational groups independently of their service grade, or task and they concern oneself.
Initially, the clinical picture of PTSD was used t o describe the problems of people that suffered from a railway accident but had no obvious evidence of injury – this was called “railway-spine". This term emerged in the midst of the 19th century with Erichsen . Subsequent writers stressed the effect of anxiety and terror as a psychological dimension. As a result, Page (1883) launched the concept of “general nervous shock", which was used as a pretext by the railway companies to disallow any indemnity claims for there were no specific physical damages. During the First World War, a very carefully estimated number of 60,000 German soldiers was diagnosed with what is called complex PTSD today and back then was named “shell shock" or “war neurasthenia", “gas neurosis" or “soldiers heart". In later years, the survivors of World War II, the Vietnam war and its consequences contributed to the introduction of the term PTSD in the DSM III in 1980 .
Within the workplace there are a range of events which can potentially cause PTSD, these include: experiencing another person’s death, witnessing physical, emotional or psychological harm that threatens one’s safety or the stability of one’s world (e.g. accidents, medical interventions, physical assaults or military experience). In short, such traumatic events can cause significant psychological trauma.
Nurses, social workers, emergency medical service and psychosocial helpers bear the risk of experiencing attacks by patients, being confronted with the death of people (especially traumatizing is the death of a child) and colleagues and experiencing the suffering of others without being able to help.
Fire-fighters and police officers are prone to being attacked, witnessing the death or suicide of colleagues, having to shoot another person, being injured themselves or experiencing the threat to their own lives.
Engine drivers, bank employees and journalists are particularly confronted with robberies, serious accidents or being assaulted and threatened themselves when reporting from troubled areas.
These traumatic events may be single (Type I Trauma), continuous, or repetitive incidents (Type II Trauma) that render inadequate one's ability to cope with the resulting feelings. More specifically, Type-I-trauma are mostly short-term events and are characterised by acute danger to life, suddenness and surprise; whilst, in contrast, Type-II-trauma are long-term events characterised by a series of different single traumatic events and low predictability of the further course of events. Table 1 gives an overview of the types of trauma and their associated causes.
Table 1 Types of trauma and their causes
|Type-I-trauma (single, short-term)||Type-II-trauma (repeated, long-term)|
|Accidental trauma||Serious accident, work-related trauma (police, fire service, emergency medical service), short-term catastrophes (blaze, hurricane)||Long-term catastrophes (quakes, flood), technical catastrophes (toxic gas)|
|Interpersonal trauma (man-made)||Sexual abuse (rape), criminal or physical violence; civilian experience of violence (bank hold-up)||Sexual and physical abuse in childhood; war, torture, hostage-taking, political imprisonment|
Clinical picture of PTSD
From a clinical perspective, there are five main criteria that have to be met for the diagnosis of PTSD according to the International Classification of Diseases ICD-10 . These include:
- The exposure to a traumatic event of an exceptionally threatening or catastrophic nature, which is likely to cause pervasive distress in almost anyone.
- There must be persistent remembering or reliving of the stressor in intrusive flashbacks, vivid memories or recurring dreams, or in experiencing distress when exposed to circumstances resembling or associated with the event.
- The individual must exhibit an actual or preferred avoidance of circumstances resembling or associated with the stressor.
- Either of the following must be present: a) inability to recall, either partially or completely, some important aspect of the period of exposure to the event; or b) persistent symptoms of increased psychological sensitivity and arousal.
- The onset of symptoms follows the trauma with a latency period which may range from a few weeks to six months. In rare cases the symptoms may occur after a longer period than six months when, for example, an anniversary or some other flash point took place (Late-Onset-PTSD).The duration of symptoms is at least one month.
The main symptoms of PTSD are either the so-called intrusions which are involuntary recurring and vivid, detailed trauma-memories, or nightmares of the trauma, or having flashbacks, which means experiencing attacks of memories that are characterized by their suddenness and liveliness and accompanied with the feeling of reviving the trauma. These are often triggered by specific stimuli such as trauma-related objects, noises or associated smells. The person tries to avoid those triggers, which in extreme cases, leads to avoiding certain places or people or watching TV shows completely. When confronted with circumstances associated with the stressor, suffering individuals experience involuntary physical reactions, such as: sweating, trembling, breathing difficulties, palpitations, nausea or intense fear . Furthermore, the person affected by PTSD can exhibit signs of increased psychological sensitivity and arousal in having difficulty of falling or staying asleep, an irritability sometimes accompanied by outbursts of anger, difficulty concentrating, an extreme alertness regarding his/her surroundings (e.g., screening the surrounding with respect to potential threats, and the difficulty to calm down after having been frightened).
Other forms of reactions to trauma
Discrimination between PTSD and other forms of psychological reactions to traumatic events is crucial for the selection of adequate treatments. Besides PTSD, other reactions to traumatic events include the following.
- Acute stress reaction: This differs from PTSD through manifestation of dissociative symptoms, such as an initial state of "daze" with some narrowing of attention and disorientation, followed by withdrawal from the surrounding situation, or by agitation. The symptoms last from a minimum of 2 days and a maximum of 4 weeks, and occur within 4 weeks of the event.
- Adjustment disorder: This is most commonly used for events that are not traumatic in the sense of trauma definition (mobbing, divorce, job loss). The symptoms lack the intensity of those of PTSD; instead of that depression and anxiety prevail. Usually, there are no intrusive symptoms and no avoidance behaviour.
- Anxiety disorder / Specific phobia: Anxiety disorders are characterised by physical reactions due to the confrontation of memories or a fear-related stimulus. Also, a phobic avoidance of thoughts and situations is a prominent feature of phobias or anxiety disorders. If it is the case that victims of traffic accidents display serious avoidance behaviour (e.g. driving a vehicle) without having a psychologically chronic arousal or intrusive memories, the diagnosis of a specific phobia should be considered.
The clinical diagnostics instruments are of two kinds :
- Structured and standardized interviews (e.g. Clinician-Administered PTSD Scale )
- Methods of self-assessment (e.g. Impact of Event Scale)
Self-assessments are easy and quick to administer and have been shown as sufficiently sensitive and specific regarding the diagnosis of PTSD, and are useful in estimating the severity and symptom frequency.
The spread and incidence of PTSD depends on the frequency of traumatic events. At least some types of trauma (e.g., the risk of experiencing torture or political persecution or being confronted with heavily injured people) vary in their frequency across political regions, countries with civil wars and regions with many natural disasters, as well as occupational groups. With epidemiological data it is, therefore, important to consider their regional origins and prevalence.
The majority of the population (about 60 to 89 per cent) will be confronted with a traumatic event once in their lives . The most frequent traumas cited in different studies were the death of a loved one, acts of war, serious accidents and witnessing accidents or workplace violence . However, it is important to stress that not every traumatic event provokes the occurrence of PTSD.
When it comes to prevalences of PTSD in general population, a German study found a 1-year-prevalence for PTSD to be 2.3 per cent for the life-span of 18 to 97 years . With the ICD-10 definition criteria of PTSD in contrast to DSM-IV criteria the prevalence was twice as high. The US-American National Comorbidity Study found a lifetime prevalence of 7.8 per cent with significant gender difference (women 10.4 per cent, men 5.0 per cent) . The replication of this study 12 years later found a lifetime prevalence of 6.3 per cent. Perkonigg and colleagues  found a lifetime prevalence of 7.8 per cent to 9.2 per cent in Germany. In 2011, about 7.7 million people in the EU-27 were affected by PTSD . The DALY (Disability Adjusted Life Years Lost) rate per 10000 persons for PTSD is 8.4 years for woman and 3.4 years for man. The highest DALY rate per 10000 persons is a cumulative 134.4 years for female unipolar depression and 82.8 years for alcohol use disorders in men  – which are both one of the most frequent PTSD-accompanying diseases. Only 26 per cent of all cases with mental disorders had any consultation with professional health care services . Together with additional epidemiological evidence for selected neurological conditions, the total EU-25 cost burden of mental disorders in 2005 was estimated to be close to 277 billion Euros . The fourth European Survey on Working Conditions  has shown that the risk of experiencing violence and harassment, which are among the most important work-related circumstances possibly leading to development of PTSD, is very high in health sectors (16.4 per cent) and in public administration sector (11.3 per cent).
The specific prevalence rates for these occupational groups at risk are presented below.
Health and social care
In the health and social care sector, workers are particularly exposed to the risk of violent behaviour. When it comes to violence at work, Poster and Ryan  discovered that 76 per cent of all nurses working with mentally ill people were seriously attacked at least once by patients in their careers, while Guterman and colleagues (1996)  discovered the same with one fifth of American and Isreali social workers. 8,5 % of all nurses met the criteria for PTSD in another study .
When the emergency medical service is investigated, 95 percent of German workers reported at least one extreme emotional strain in their careers . One fifth had experienced the death or suicide of a colleague. Of these, 21 to 36 percent fulfilled the criteria for PTSD . A total of 10 % developed PTSD according to a study investigating rescue workers worldwide .
Almost every health worker in intensive care had experienced an extreme emotional strain at least once (99 per cent) . Nearly two thirds were confronted with the death of children and 31 per cent with the suicide of a colleague. Of these, 41 per cent had developed PTSD.
Helpers like social workers, psychologists and non-professional volunteers who take care of survivors, relatives and the emergency services run the risk of secondary traumatisation, which is the stress resulting from helping or wanting to help a traumatised person. Raphael and colleagues  compared these helpers with emergency services personnel and found no difference in the extent of psychosocial symptoms and aftermath.
Studies of fire-fighters reveal that: 96 per cent experienced extreme emotional strain and 80 percent had been in danger of their lives; 60 percent had been injured; one fifth had experienced the death or suicide of a colleague, of these 9 percent developed a PTSD . International studies have found similar prevalence rates .
The situation for police officers seems similar. An estimated, 100 percent of police officers had been confronted with traumatic stressors, and most of them had been in danger of their lives and had been injured. More than half had to make use of their firearms, with an estimated one fifth had experienced the death of a colleague and one half the suicide of a colleague. Approximately, 5 to 13 percent of all police officers develop PTSD . In special units PTSD rates may even rise to 50% .
Another study found that the prevalence of PTSD for police officers and fire-fighters ranged from 6 per cent to 32 per cent . The prevalence of PTSD was generally less than that found among victims themselves, but higher than general community prevalence.
In other sectors, bank employees are susceptible to experiences of violence. One quarter of bank clerks had experienced a robbery and of these 14% developed a PTSD .
Engine drivers are confronted once or twice during their careers with serious accidents, 2% are impaired in the long-term by posttraumatic stress symptoms. Similar low prevalence findings were also noted by other studies .
Journalists are another high-risk group that have not been focused on a lot. Teegen and Grotwinkel  surveyed 61 international journalists and found that 13 per cent had developed PTSD after being confronted with death, violence and perishing or after being assaulted and threatened themselves when reporting from troubled areas.
Studies suggest that a large number of people suffering from PTSD are diagnosed also with a second disease. Depending on the study, between 50-100% of patients with PTSD have accompanying disorders which include: anxiety, depression,, substance abuse, somatisation, borderline personality disorder and cardiovascular disease. Suicidal tendencies, for example, have been found eight times as often in former soldiers with PTSD in comparison to general population . Different authors  pointed to the fact that those diseases are mostly connected somehow chronologically or with regards to contents to the trauma and are not independent.
Course of disease
Spontaneous remissions have been reported in one third of patients within the first 12 months and in one half of patients after 4 years. Ten years after the traumatic event the symptoms continued to exist in about one third of patients. One half of those who received treatment were symptom-free after 3 years . A delayed onset of PTSD may occur after symptom-free years or even decades (Late-Onset-PTSD). An exacerbation of pathology is possible in the context of critical life events or role changes .
Risk factors that influence the development of PTSD, its symptoms, course and remission can be divided into three groups.
Pretraumatic risk factors
Different studies show that traumatization at a young age, a prior history of psychological problems or trauma, major life stressors (such as, divorce and chronic medical illness), as well as a low level of education or socioeconomic status or unemployment are risk factors at a pretraumatic-level. These provide a certain susceptibility to the development of PTSD after experiencing trauma in the workplace .
Personality traits, such as high neuroticism (characterized by anxiety, moodiness and a tendency to be in a negative emotional state) and lower levels of agreeableness (when the person is perceived as warm and cooperative) and conscientiousness, seem to moderate adjustment processes and contribute to the development of PTSD. Lower levels of efficacy (the ability to perceive goals as reachable and the expectation to successfully influence your environment) and an external locus of control as the contrary of it can also be contributing factors  [.
When it comes to coping strategies, denial, less use of relationship-focused coping and avoidance styles are associated with PTSD symptoms .
As far as gender differences are concerned, the findings are inconsistent . Women exhibit a greater lifetime prevalence of PTSD than men. In studies among US citizens that are transferable to the European population, men are confronted more frequently with traumatic situations than women (61 to 91 per cent vs. 51 – 87 per cent) , whereas women find themselves more often in situations with a high traumatizing potential like “Type-II-traumata" and interpersonal traumata (e.g., sexual violence, rape).
These predisposing factors may lower the threshold for the development of the syndrome or to aggravate its course, but they are neither necessary nor sufficient to explain its occurrence. In fact, they tend to have a smaller impact than peri- and posttraumatic factors .
Peritraumatic risk factors
Peritraumatic risk factors are the characteristics of the event. These include: frequency, duration and repetition of the trauma that promote the development of PTSD .The frequency of exposure to critical incidents also diminishes an individual’s capacity to cope and promotes PTSD development .
An initial reaction to the trauma that is emotionally extreme or the development of an acute stress disorder (please see 3.5) may contribute to the occurrence of PTSD . The same applies to a state of consciousness called dissociation while trauma is happening; however these are not experienced by all persons. In the dissociative state the person feels emotionally numb or detached from environment or not at all capable of emotional reactions. Normal perception is then impaired, the environment may seem unreal, and the person can feel disconnected from his/her body.
In all occupational groups the exposure to dead bodies or body parts, especially those of children , as well as the death of colleagues are also risk factors .
Posttraumatic risk factors
Several factors contribute to the maintenance or exacerbation of PTSD symptoms. Lack of social support or even negative reactions invalidates the support from the organization can overburden the person and are predictive of PTSD .
Also, having difficulties in expressing feelings about the event (disclosure) and a lack of willingness to confront the emotional meaning of the trauma is related to the reporting of PTSD symptoms . The same was found for the denial of need for help . Furthermore, the stress amounting from the difficulties of everyday life and the extent of loss in the aftermath of the event like physical damage or the loss of one’s home or a comrade promote the risk of disease .
With respect to emotional processes in the aftermath, a feeling of helplessness due to role ambiguity or bad training, a lack of appreciation from others (including, critical comments), coverage in the media and by the public, as well as a strong identification with the victims themselves and their families were risk factors for the development of PTSD . Also, surviving a traumatic event may lead to a feeling of survivor guilt that increases the likelihood of the occurrence of PTSD .
This section introduces strategies for prevention, treatment and rehabilitation in cases of work-related PTSD. A preventative approach is strongly emphasised in occupational settings. To reduce the risk of PTSD development, the demands imposed on the person have to be decreased and mobilisation of resources maximised. As a first step, traumatic situations in a working context should be avoided as far as this is possible. At a secondary level, the goal is to help the person to master the traumatic situation with the personal and organisational resources available. Just the last step is to indicate suitable ways of dealing with the disorder when symptoms are present. For the first and second level interventions, the following strategies have been found to be useful with regard to what employers could do and what can be done on an organizational level, as the both of them intertwine.
Concerning negative reactions and violence like verbal aggression at the workplace a zero-tolerance-policy is crucial. It is important that superiors (employers) show a strict attention to negative reactions amongst colleagues when employees talk about distressing incidents, and to even small episodes of violence at the workplace.
Furthermore, superiors are role models with regard to the expression of feelings and handling of emotional strain experiences and should be well trained in personnel management and leadership .
Clear work assignments and professional roles (hierarchy and responsibilities) in the organisational structure are important as they offer protection against emotional strain and feelings of helplessness. Job specifications and clear assignments of superiors define the limitations of one’s working role and the responsibilities of it. Thereby, they relieve from false expectations and guilt feelings and forward a feeling of control.
The possibility of supervision as a means of counselling for people engaged in working with people also constitutes a protective factor against emotional distress in general and distress resulting from a specific event. It fosters the handling of problems (problem solution) in a structured way and ensures progress in expertise as well as the dealing with a possibly traumatic event .
Before the possible traumatic event
Personnel selection based upon the identification of individual risk factors seems relevant when it comes to the assignment of tasks with the potential to be highly-traumatizing incidents. Persons with pretraumatic risk factors should be carefully screened and rarely allocated to such operations. Up until now, such allocation has proven difficult, because the critical amount or extent of risk factors that promote PTSD development are currently not clear and seemingly impossible to detect. More importantly, there is an important question of how ethical such an approach would be.
Medical screenings and fitness evaluations are relevant for occupational groups like police officers, fire-fighters and emergency medical services as they appear to deteriorate physically as years of service increase . This may lead to deteriorating job performance, due to which the person is exposed to more high-risk situations.
Of high importance is the preparation of tasks that can be conducted in specific occupational groups, with the primarily focus on being on preparing workers to cope with possible traumatizing events . Some measures include:
- the cognitive preparation of distressing operations and situations
- the simulation of dangerous situations and emergencies
- the automation of procedures
- training courses on stress management
- the development of realistic performance expectations 
- training in the cognitive-behavioural skills of problem solving approaches
- crisis decision making 
- training in basic communication skills when taking care of victims 
- the provision with operational guidelines 
When having been on a longer leave, e.g. in operations abroad (soldiers), the preparation of return is essential to ensure the first detachment and adjustment when coming back home .
During the possible traumatic event
Large-scale emergency situations mostly require an On Scene Support Service of qualified persons and psychologists . It is important to highlight the importance of exchange concerning traumatizing experiences with colleagues, particularly when it comes to male-dominated occupations where members are less willing to open up to out-group members or to accept help at all. High group cohesion is predictive of good coping .
After the possible traumatic event
Psychological debriefing is a standardised method consisting of different stages that contain the report about facts on the course of the traumatic event, the report about the person’s most important thoughts, feelings and reactions including the “hot spot" of the trauma, the education about traumatic stress responses, symptoms and coping strategies. The most common form of debriefing is the “Critical Incident Stress Debriefing" (CISD), which was developed for fire-fighters and emergency medical service teams and is a part of “Critical Incident Stress Management" (CISM). The debriefing is conducted in groups of 4-30 participants promptly following the traumatic event and usually takes 2 to 3 hours .
Different studies show conflicting findings regarding the standardised approach of debriefings, the early point of the intervention, the focus on symptoms and peer pressure in the group settings during such discussions . Some studies even found an exacerbation of PTSD symptoms after debriefing . Therefore, it is suggested that debriefings should :
- focus on the message that the reaction of the person is a normal reaction to extreme circumstances;
- be conducted solely voluntarily;
- ideally not conducted when persons show high pretraumatic strain and risk factors as well as dissociative symptoms;
- should not be conducted with type-II-trauma; and
- be conducted by persons with established knowledge of psychotraumatology
Psychoeducation that contains information about traumatic stress responses, PTSD and Acute Stress disorder, grieving processes and efficient treatment possibilities should be provided to employees .
Screenings of developing symptoms seem reasonable when the first strains of the traumatic event have diminished. Mild symptoms in the first four weeks require just “watchful waiting" and a follow-up meeting within a month .
Short breaks for highly strained persons with single symptoms after a traumatic event are an appropriate measure to reduce distress and to keep away from emerging emotional demands . Prevention strategies should always be embedded in a master plan of follow-up treatment. The possibility of mid-term and long-term follow-up care is crucial.
The following paragraph gives a short summary of current treatment possibilities of PTSD which should be offered by employers as an external help.
Elements of therapy comprise the stabilisation and regulation of affect, increased exposure of trauma and integration as well as re-orientation. In particular, the part of exposition appears as relevant for the improvement of symptoms. Trauma-focused methods can be classified into expositions-focused therapies and cognition-focused ones, with the latter trying to change patterns of thoughts and attitudes gained due to trauma . The most efficient of them concerning alleviation of symptoms are shortly described :
The Exposition-focused therapy assumes that a repeated imaginative reviving of the traumatic event and a repeated exposition to secure but avoided situations leads to a habituation of the patient who reminds the trauma without undergoing an extreme fear response .
Cognitive processing therapy aims to detect and reduce avoidance behaviour like rumination, suppression of thoughts, selective attention, behaviour to avoid anxiety and the numbing of emotions .
The purpose of EMDR (Eye Movement Desensitization and Reprocessing) is to integrate the fragmented memories of the trauma by focusing the patient on an external bilateral stimulus (tactile, acoustic) while at the same time they reprocess the trauma and establish new associations .
The pharmacotherapy of PTSD is merely a supplement to psychotherapy and indicated only when severe symptoms of hyperarousal, panic attacks and depression are present. Tranquilizers should be prescribed only on rare occasions.
Post-treatment and rehabilitative measures mainly include the family care in the aftermath of a traumatic event by providing information, advice and further help ; postdeployment strategies that facilitate a gradual reintegration into job and offers for talk by experienced colleagues .
The appreciation of the achieved work by peer-group members and relatives is a main component in coping with traumatic events .
Health surveillance by annual medical examinations and monitoring of symptoms are also part of rehabilitative care. Stress inoculation training can be implemented to foster distancing techniques, imagination exercises for self-awareness and handling of emotion . It helps people in managing their anxiety and stress early enough before it gets out of control by providing coping skills as muscle relaxation and deep breathing. On an organizational level, the development of quality standards for psychosocial measures that are provided and the networking of treatment services like the collaboration of crisis intervention with long-term treatments seem necessary to ensure the establishment of an effective health care concerning PTSD.
It is the task of the organization to collaborate with the mass media in order to dose the type and extent of information given to public and to regulate potential critical reactions that may additionally strain field personnel is important .
Stress responses to emotional strain are a normal reaction to extreme traumatic events that exceed the person’s coping skills and resources, which have to be restored by appropriate measures of prevention, treatment and rehabilitation.
Particularly in occupational groups at risk, prevention strategies are an important measure with regard to the prevention of the development of PTSD. These strategies affect the areas of screening for risk factors and personnel selection, preparation of tasks, psychological debriefings and characteristics of corporate culture as well as social support and appreciation.
 Maercker, A. ‚Posttraumatische Belastungsstörungen, Springer Verlag, Berlin, 2009.
 Clohessy, S., Ehlers, A., ‘PTSD symptoms, response to intrusive memories and coping in ambulance workers‘, British Journal of Clinical Psychology, 38, 1999, pp. 251-265.
 WHO – World Health Organisation, ICD-10 , International Statistical Classification of Diseases and Health Related Problems, Tenth Revision, World Health Organization, 1994.
 Blake, D.D., Weathers, F.W., Nagy, L.M., Kaloupek, D.G., Gusman, F.D., Charney, D.S., Keane, T.M. ‘The development of a clinician-administered PTSD scale’, Journal of Traumatic Stress, 8, 1995, pp. 74-90.
 Breslau, N., Kessler, R.C., Chilcoat, H.D., Davis, G.C., Andreski, P. ‘Trauma and post-traumatic stress disorder in the community’, Archives of General Psychiatry, 55, 1998, pp. 632-636.
 Maercker, A., Forstmeier, S., Wagner, B., Glaesmer,H., Brähler,E. ‘Posttraumatische Belastungsstörungen in Deutschland: Ergebnisse einer gesamtdeutschen epidemiologischen Untersuchung‘, Nervenarzt, 5, 2008, pp. 577-586.
 Kessler, R.C., Sonnega, A., Bromet, E., Hughes, M., Nelson,C.B. ‘Posttraumatic stress disorder in the national comorbidity survey’, Archives of General Psychiatry, 52, 1995, pp. 1048-1060.
 Perkonigg, A., Kessler, R.C., Storz, S., Wittchen, H.U. ‘Traumatic events and post-traumatic stress disorder in the community: Prevalence, risk factors and comorbidity’, Acta Psychiatrica Scandinavica, 101, 2000, pp. 45-59.
 Wittchen, H.-U, Jacobi, F., Rehm, J., Gustavsson, A., Svensson, M., Jönsson, B., Olesen, J., Allgulander, C., Alonso, J., Faravelli, C., Fratiglioni, L., Jennum, P., Lieb, R., Maercker, A., van Os, J., Preisig, M., Salvador-Carulla, L., Simon, R., Steinhausen, J.-C. ‘The size and burden of mental disorders and other disorders of the brain in Europe 2010’, European Neuropsychopharmacology, 21, 2011, pp. 655–679.37
 Kessler, R.C. (Ed.), The WHO World Mental Health Surveys: Global Perspectives on the Epidemiology of Mental Disorders, Cambridge University Press, New York, 2008.
 Wittchen, H.-U., Jacobi, F. ‘Size and burden of mental disorders in Europe - a critical review and appraisal of 27 studies’. European Neuropsychopharmacology, 15 (4), 2005, pp. 357–376.
 Eurofound – European Foundation for Improving Living and Working Conditions, Fourth European Working Conditions Survey, Publications Office of the European Union, Luxembourg, 2009.
 Poster, E.C., Ryan, J. ‘A multiregional study of nurses‘ beliefs and attitudes about work safety and patient assault’, Hospital and Community, 45, 1994, pp. 1104-1108.
 Guterman, N.B., Jayaratne, S., Gargal, D. Workplace violence and victimization experienced by social workers: A cross-national study of Americans and Israelis, In: Van den Bos, G.R., Bulatao, E.Q. (eds.), Violence on the job. Identifying risks and developing solutions. American Psychiatric Association, Washington DC, 1996, pp.175-188.
 Adriaenssens, J., de Gucht, V., Maes, S., ’The impact of traumatic events on emergency room nurses: Findings from a questionnaire survey’, International Journal of Nursing Studies, 49, 2012, pp.. 1411–1422.
 Teegen, F., Yasui, Y., ‚Traumaexposition und Posttraumatische Belastungsstörung bei dem Personal von Rettungsdiensten‘, Verhaltenstherapie und Verhaltensmedizin, 21, 2000, pp. 65-83.
 Berger, W., Coutinho, E.S., Figueira, I., Marques-Portella, C., Luz, M.P., Neylan, T.C., Marmar, C.R., Mendlowicz, M.V. ‘Rescuers at risk: a systematic review and meta-regression analysis of the worldwide current prevalence and correlates of PTSD in rescue workers’, Psychiatry and Psychiatric Epidemiology, 47, 2012, pp. 1001–1011.
 Teegen, F., Müller, J., ‚Traumaexposition und Posttraumatische Belastungsstörung bei Pflegekräften auf Intensivstationen‘, Psychotherapie, Psychosomatik und medizinische Psychologie, 50, 2000, pp. 384-390.
 Raphael, B., Singh, R., Bradbury, B., Lambert, F. ‚Who helps the helpers? The effects of a disaster on the rescue workers’,. Omega, 14, 1983/84, pp. 9-20.
 Teegen, F., Domnick, A., Heerdegen, M., ‚Hochbelastende Erfahrungen im Berufsalltag von Polizei und Feuerwehr: Traumaexposition, Belastungsstörungen‘, Bewältigungsstrategien. Verhaltenstherapie und psychosoziale Praxis, 29, 1997, pp. 583-599.
 Teegen, F. Posttraumatische Belastungsstörungen bei gefährdeten Berufsgruppen: Prävalenz - Prävention – Behandlung, Huber, Bern, 2003.
 Kopel, H., Friedmann, M., ‘Posttraumatic symptoms in South African police exposed to violence’, Journal of Traumatic Stress, 10, 1997, pp. 367-317.
 McFarlane, A.C., Williamson, P. Barton, A.C., ‘The impact of traumatic stressors in civilian occupational settings’, Journal of Public Health Policy 30, 2009, pp. 311-327.
 DeBoer, C., Steffgen, G., Bollendorff, C. ‚Diagnose der Posttraumatischen Belastungsstörung bei Bankangestellten nach einem Überfall‘, Arbeitsmedizin, Sozialmedizin, Umweltmedizin, 34, 1999, pp. 315-319.
 Teegen, F., Grotwinkel, M., ‚Traumatische Erfahrungen und Posttraumatische Belastungsstörungen bei Journalisten. Eine internet-basierte Studie‘, Psychotherapeut, 46, 2001, pp. 169-175.
 Davidson, J.R., Hughes, D., Blazer, P.G., George, J.K. ‚’Posttraumatic stress disorder in the community. An epidemiological study’, Psychological Medicine, 21, 1991, pp. 713-721.
 Violanti, J.M., Paton, D., (Eds.) Who gets PTSD? Issues of Posttraumatic Stress Vulnerability, Charles C. Thomas, Springfield, Illinois, 2006.
 Regehr, C., Hill, J., Glancy, G.D., ‘Individual predictors of traumatic reactions in firefighters’, Journal of Nervous and Mental Disease, 188, 6, 2000, pp. 333-339.
 Moos, R.H., Holahan, C.J., ‘Dispositional and contextual perspectives on coping: Toward an integrative framework’, Journal of Clinical Psychology, 59, 12, 2003, pp. 1387-1403.
 King, D.W., King, L.A., Foy, D.W., Keane, T.M., Fairbank, J.A. ‘PTSD in a National sample of female and male Vietnam veterans: Risk factors, war-zone stressors, and resilience-recovery variables’, Journal of Abnormal Psychology, 108, 1999, pp. 164-170
 Haisch, D.C., Meyers, L.S., ‘MMPI-2 assessed posttraumatic stress disorder related to job stress, coping, and personality in police agencies’, Stress and health, 20, 2004, pp. 223-229.
 McFarlane, A.C., Risk factors for the acute biological and psychological response to trauma, In: Yehuda, R. (ed.), Risk factors for posttraumatic stress disorder ,American Psychiatric Association, Washington DC, 1999, pp.163-190.
 Brewin, C.R., Andrews, B., Valentine, J.D. ‘Meta-analysis of risk factors for posttraumatic stress disorder in trauma-exposed adults‘, Journal of Consulting and Clinical Psychology, 68, 2000, pp. 748-766.
 Pieper, G., Maercker, A., ‘Männlichkeit und Verleugnung von Hilfsbedürftigkeit nach berufsbedingten Traumata‘, Verhaltenstherapie, 9, 1999, pp. 222-229.
 Ursano, R.J., Gringer, T.A., McCaroll, J.E. ‚Prevention of post-traumatic stress. Consultation, training, and early treatment, In: van der Kolk, B.A., McFarlane, A.C., Weisaeth, L. (eds.), Traumatic Stress. The effects of overwhelming experience on mind, body, and society , Guilford New York, 1996,. pp. 441-462.
 Violanti, J.M., ‘Stress patterns in police work: A longitudinal analysis’, Journal of Police Science and Administration, 11, 1983, pp. 211-216.
 Paton, D., Jackson, D., ‘Developing disaster management capability: An assessment centre approach’, Disaster Prevention and Management, 11, 2002, pp. 115-122.
 Helmerichs, J., Psycho-soziale Notfallversorgung im Großschadensfall und bei Katastrophen, In Lasogga, F., Gasch, B.,(eds.), Notfallpsychologie. Ein Lehrbuch für die Praxis,. Springer, Berlin, 2008, pp. 371-388.
 Bolwig, T.G., ‚Debriefing after psychological trauma‘, Acta Psychiatrica Scandinavica, 98, 1998, pp. 169-170.
 Brauchle, G., Juen, B., Beck, T., Effizienz von Debriefings. In Schönherr, C., Juen, B., Brauchle, G., Beck, T. & Kratzer, D. (edes), Belastungen und Stressverarbeitung bei Einsatzkräften. Aktuelle Forschungsergebnisse der Arbeitsgruppe Notfallpsychologie der Universität Innsbruck , Studia Universitätsverlag, Innsbruck, 2005, pp. 39-47.
 Bisson, J.I., Jenkins, P.L., Alexander, J., Bannister, C., ‘Randomized controlled trial of psychological debriefing for victims of acute burn trauma’, British Journal of Psychiatry, 171, 1997. pp. 78-81
 NICE - National Institute of Clinical Excellence, (Post-traumatic stress disorder – the management of PTSD in adults and children in primary and secondary care, National Clinical Practice Guideline No 26, Gaskell & the British Psychological Society, London, 2005. Available at: https://www.nice.org.uk/guidance/ng116/evidence/march-2005-full-guideline-pdf-6602623598
 Resick, P.A., Calhoun, K.S. Posttraumatic stress disorder. In Barlow, D.H. (Ed.), Clinical handbook of psychological disorders: A step-by-step treatment manual, 3rd edition Guilford Press, New York, NY, 2001, pp. pp. 60-113.
 Williams, M., Cahill, S., Foa, E., Psychotherapy for Post-Traumatic Stress Disorder. In Textbook of Anxiety Disorders, , In: Stein, D., Hollander, E., Rothbaum, B (eds.), American Psychiatric Publishing, Second Edition, 2010.
 Shapiro, F., Forrest, M., EMDR, Basic Books, New York, 1997.
Javidi, H., Yadollahie, M. ‘Post-traumatic Stress disorder’, International Journal of Occupational and Environmental Medicine, 3 (1), 2012. Available at: http://www.theijoem.com/ijoem/index.php/ijoem/article/viewFile/127/233
Kindta, M., Engelhard, I.M. ‘Trauma processing and the development of posttraumatic stress disorder’, Journal of Behavior Therapy and Experimental Psychiatry, 36, 2005, pp. 69–76.
Bronisch, T. ‘History of the diagnosis of a Posttraumatic Stress Disorder’ , Psychotherapie 15. Jahrg. , 15 (2), 2010, pp. 195-203. Available at: http://cip-medien.com/media/download_gallery/10-02/04.Bronisch.pdf
Breslau, N., Anthony, J.C. ‘Gender Differences in the Sensitivity to Posttraumatic Stress Disorder: An Epidemiological Study of Urban Young Adults’, Journal of Abnormal Psychology, 116 (3), 2007, pp. 607–611.
Iennaco, J., Dixon, J., Whittemore, R., Bowers, L. ‘Measurement and Monitoring of Health Care Worker Aggression Exposure’ , OJIN: The Online Journal of Issues in Nursing, 18 (1), 2013, Manuscript 3.
Martin, M., Marchand, A., Boyer, R., Martin, N. 'Predictors of the Development of Posttraumatic Stress Disorder Among Police Officers', Journal of Trauma & Dissociation,10 (4), 2009, pp. 451 — 468.
Collins, P.A., Gibbs, A.C.C. ‘Stress in police officers: a study of the origins, prevalence and severity of stress-related symptoms within a county police force’, Occupational Medicine, 53, 2003, pp. 256–264.
Zeev, K., Iancu, I., Bodner, E. ‘A review of psychological debriefing after extreme stress’. Psychiatric Services, 52 (6), 2001, pp. 824-827.