**2. The relationship between disasters and Posttraumatic Stress Disorder (PTSD)**

Breslau et al. (1991) estimated that 6% to 7% of the US population is exposed to disaster or trauma every year, while Wang et al. (2000) showed that natural disasters affect an average of approximately 200 million people in China every year, several thousand of whom do not survive. In the aftermath of these catastrophic events, PTSD is one of the most common psychiatric diseases suffered by post-disaster survivors.

The prevalence of PTSD ranged from 3.0% to 34.3% in Taiwan after the 1999 earthquake (Chou et al., 2004a,b), it was approximately 25% in Turkey after the 1999 earthquake (Tural et al., 2004), and it was reported as 74% in Armenia after the 1988 earthquake (Armen, 1993). In a systemic review of the literature, Andrews, Brewin, Philpott, & Stewart (2007) found that delayed-onset PTSD in the absence of any prior symptoms was rare, whereas delayed onset that represented exacerbations or reactivations of prior symptoms accounted for, on average, 38.2% and 15.3% of military and civilian cases of PTSD, respectively. Generally, the lifetime and current prevalence rates for psychiatric disorders range anywhere from 1% to 74% (Breslau, Davis, Andreski, & Peterson, 1991; Carr et al., 1995; Chang et al., 2003; Chou et al., 2003; Tainaka et al., 1998), with women twice as likely as men to be affected. Furthermore, women report more symptoms of anxiety and depression than men (Chou et al., 2003; Chang et al., 2003).

Risk Factors and Hypothesis for Posttraumatic

(Maj et al., 1989; Rubonis & Bickman, 1991).

2011).

al., 2008).

**6. The risk factors of PTSD** 

**6.1 Demographic data** 

**6.2 Biological factors** 

Stress Disorder (PTSD) in Post Disaster Survivors 145

Perkonigg, Kessler, Storz, Wittchen, 2000). For example, the combination of PTSD and panic and phobic disorders is an important predictor for PTSD chronicity (McFarlane & Papay, 1992; Ursano, Kao, & Fullerton, 1992). Furthermore, the rate of psychopathology is higher in post-disaster groups than in either the same groups prior to trauma or in control groups

Researchers focusing on survivors of the Chi-Chi earthquake in Taiwan (Su, Chou, Lin, Tsai, 2010) have found evidence of psychological sequelae that includes posttraumatic stress disorder (PTSD), major depressive disorder, sleep disorder, anxiety, and substance abuse (Chou et al., 2004a, 2004b, 2005, 2007; Chen et al., 2001; Chang et al., 2002; Lai et al., 2004; Hsu et al., 2002; Kuo et al., 2003; Liu et al., 2006; Tsai et al., 2007; Wu et al., 2006; Yang et al., 2003). The quality of life for survivors of traumatic events who develop psychiatric illnesses or impairments is worse than that for survivors without any psychiatric illness (Chou et al., 2004b; Tsai et al., 2007; Wu et al., 2006). In addition, rescue workers such as nurses, fire fighters, and soldiers may develop physical or mental impairments (Chang et al., 2008; Liao et al., 2002; Shih et al., 2002; Yeh et al., 2002). We used PubMed to identify Chi-Chi earthquake-related papers published through June of 2009. All of the Chi-Chi earthquake papers related to psychiatry are summarized in Table 1 (cited from Su, Chou, Lin, Tsai,

Researchers who study risk factors for PTSD have identified aspects of demographic data, psychological factors, psychiatric symptoms, and post-trauma social resource factors as

Some researchers who have examined gender differences suggest that females are more likely than males to develop PSTD (Chou et al., 2005; Helzer, Robins, & McEvoy, 1987; Johnson & Thompson, 2008; Lazaratou et al., 2008). A possible explanation for this is the specific reactions that result from feminine characteristics to a traumatic event (Chou, Tsai, Wu, Su, & Chou, 2006). Additionally, there are previous studies that have associated old age with an increased risk of developing PTSD (Goenjian et al., 1994; Lewin, Carr, Webster, 1998). However, a recent study has suggested contradictory results (Lazaratou et

Neuroendocrine data provide evidence of insufficient glucocorticoid signaling in stressrelated neuropsychiatric disorders, while Nutt (2000) has suggested that individuals develop PTSD due to neuroendocrine dysregulation. Furthermore, impaired feedback regulation of relevant stress responses, especially immune activation/inflammation, may, in turn, contribute to stress-related pathology that includes alterations in behavior, insulin sensitivity, bone metabolism, and acquired immune responses (Raison & Miller, 2003). Because the hypothalamic-pituitary gland-adrenal axis (HPA) regulates hormone reactions during stress, PTSD severity seems to decrease when individuals exposed to traumatic

**5. Psychiatric studies of post-Chi-Chi earthquake survivors** 

important factors that contribute to the development of the disease.
