The word trauma dates back to 1690’s and it is derived from an Ancient Greek word ‘traûma’ which means physical wound and damage. In 1864, the meaning of “psychic wound, unpleasant experience which causes abnormal stress” was developed with a more psychological focus (Online Etymology Dictionary). The emphasis on the psychological aspects of trauma has emerged after World War I and II, and it has gained importance with several studies about Holocaust Survivors of the World War II (Herman, 1992).

Traumatic Events and Their Prevalence Rates

According to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR, 2000), traumatic event was defined as a personal direct or indirect experience or witnessing of an actual or threatened death, a serious injury or a threat to physical injury to self or others. As a reaction to the event, the individual need to show intense fear, helplessness or horror.

However, in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (DSM-5, 2013) the part including the subjective reactions to the traumatic event has been removed and sexual violation was specifically included in the definition of the traumatic event. Additionally, in DSM-5 (2013) being repeatedly or extremely exposed to aversive details of the traumatic event through work related exposures such as police officers being repeatedly exposed to the details of the event was included.

The lifetime prevalence rates of traumatic events differ from country to county. However, individuals from all around the world, experience or witness various types of potential traumatic events including war, sexual and physical assault or rape, robbery, being kidnapped, terrorist attacks, torture, disasters, motor vehicle accidents, life threatening illnesses, domestic violence, and child abuse (DSM-5, 2013).

In the literature, several studies have been conducted to examine the lifetime prevalence rates of experiencing at least one traumatic event. The results of these studies showed that there is a wide range of prevalence rates, which were changing from 39% to 84% (Breslau, Davis, Andreski, & Peterson, 1991; Kessler, Sonnega, Bromet, Hughes, & Nelson, 1995; Norris, 1992; Karanci, Aker, Işıklı,2009; Karanci, Aker, Işıklı, Erkan, Gül, & Yavuz, 2012; de Vries, & Olff, 2009).

Breslau et al. (1991), in their study with a sample of 1007 young adults from the city of Detroit in U.S., reported that the lifetime prevalence of exposure to traumatic events was 39.1%. Moreover, within a sample of 1000 adults equally distributed in terms of gender, age (younger, middle-aged, and older), and ethnicity (Black, or White), 690 (69%) participants experienced at least one traumatic event in their life (Norris, 1992). The results of the study conducted by Kessler et al. (1995) showed that 55.8% (N = 3277) of the participants reported that they have experienced at least one traumatic event. Furthermore, in Netherlands, de Vries and Olff (2009) conducted a prevalence research of traumatic events and they found that 80.7% of 1087 randomly selected adults with an age range of 18 to 80 reported a traumatic experience. In this study, among several traumatic events, sudden unexpected death of a loved one was the leading type of traumatic event (53.9%) and it was followed by injury or shocking experiences including motor vehicle accidents, and disasters (43.3%).

The studies focusing on traumatic events in Turkey became important after Marmara Earthquake, 1999. The study using data collected from Ankara, Kocaeli, and Erzincan was conducted to determine the effects and the prevalence rates of traumatic events in Turkey. The findings showed that 84.2% (N = 1055) of the participants experienced a traumatic event. 64% of these individuals were female, and the remaining 36% were males. Three top frequent traumatic events reported were natural disasters, the loss of a loved one, and severe accidents, fire, or explosion, respectively. Only 44.9% of the events reported by the participants of the study as traumatic met DSM-IV-TR (2000) criteria A for traumatic events (Karanci et al., 2012).